This invention relates to a series of pyrazolo[4,3-d]pyrimidin-7-ones, which inhibit cyclic guanosine 3xe2x80x2,5xe2x80x2-monophosphater phosphodiesterases (cGMP PDEs). More notably, the compounds of the invention are potent and selective inhibitors of type 5 cyclic guanosine 3xe2x80x2,5xe2x80x2-monophosphate phosphodiesterase (cGMP PDE5) and have utility therefore in a variety of therapeutic areas.
The compounds of the invention are of value for the curative or prophylactic treatment of mammalian sexual disorders. In particular, the compounds are of value in the treatment of mammalian sexual dysfunctions such as male erectile dysfunction (MED), impotence, female sexual dysfunction (FSD), clitoral dysfunction, female hypoactive sexual desire disorder, female sexual arousal disorder, female sexual pain disorder or female sexual orgasmic dysfunction (FSOD) as well as sexual dysfunction due to spinal cord injury or selective serotonin re-uptake inhibitor (SSRI) induced sexual dysfunction but, clearly, will be useful also for treating other medical conditions for which a potent and selective cGMP PDE5 inhibitor is indicated. Such conditions include premature labor, dysmenorrhoea, benign prostatic hyperplasia (BPH), bladder outlet obstruction, incontinence, stable, unstable and variant (Prinzmetal) angina, hypertension, pulmonary hypertension, chronic obstructive pulmonary disease, coronary artery disease, congestive heart failure, atherosclerosis, conditions of reduced blood vessel patency, e.g. post-percutaneous transluminal coronary angioplasty (post-PTCA), peripheral vascular disease, stroke, nitrate induced tolerance, bronchitis, allergic asthma, chronic asthma, allergic rhinitis, diseases and conditions of the eye such as glaucoma, optic neuropathy, macular degeneration, elevated intra-occular pressure, retinal or arterial occulsion and diseases characterized by disorders of gut motility, e.g. irritable bowel syndrome (IBS).
Further medical conditions for which a potent and selective cGMP PDE5 inhibitor is indicated, and for which treatment with compounds of the present invention may be useful include pre-eclampsia, Kawasaki""s syndrome, nitrate tolerance, multiple sclerosis, diabetic nephropathy, neuropathy including autonomic and peripheral neuropathy and in particular diabetic neuropathy and symptoms thereof e.g. gastroparesis, peripheral diabetic neuropathy, Alzheimer""s disease, acute respiratory failure, psoriasis, skin necrosis, cancer, metastasis, baldness, nutcracker oesophagus, anal fissure, hemorrhoids, hypoxic vasoconstriction as well as the stabilization of blood pressure during haemodialysis.
Particularly preferred conditions include MED and FSD.
PCT application PCT/IB99/00519 relates to a series of pyrazolo[4,3-d]pyrimidin-7-ones, which inhibit cyclic guanosine 3xe2x80x2,5xe2x80x2-monophosphate phosphodiesterases (cGMP PDEs).
Thus the present invention provides compounds of the formula (I): 
or a pharmaceutically or veterinarily acceptable salt thereof, or a pharmaceutically or veterinarily acceptable solvate of either entity, wherein
R1 is C1 to C6 alkyl or C3 to C6 alkenyl, C3 to C6 cycloalkyl or C4 to C6 cycloalkenyl wherein said alkyl group may be branched or straight chain and wherein
when R1 is C1 to C3 alkyl said alkyl group is substituted by;
and wherein when R1 is C4 to C6 alkyl, C3 to C6 alkenyl or C3 to C6 cycloalkyl said alkyl, alkenyl or cycloalkyl group is optionally substituted by;
one or more substituents selected from:
hydroxy;
C1 to C4 alkoxy;
C3 to C6 cycloalkyl;
phenyl substituted with one or more substitutents selected from C1 to C3 alkyl, C1 to C4 alkoxy, C1 to C4 haloalkyl, C1 to C4 haloalkoxy, halo, CN, NO2, NHR11, NHCOR12, NHSO2R12, SO2R12, SO2NHR11, COR11 or CO2R11 wherein said haloalkyl and haloalkoxy groups contain one or more halo atoms;
NR7R3, CONR7R8 or NR7COR11 wherein R7 and R8 are each independently selected from H, C1 to C4 alkyl, C3 to C4 alkenyl, CO2R9 or SO2R9 and wherein said alkyl or alkenyl groups are optionally substituted by C1 to C4 haloalkyl or C1 to C4 haloalkoxy;
Het1;
Het2 or Het3;
or R1 is Het4 or phenyl wherein said phenyl group is optionally substituted by one or more substituents selected from C1 to C4 alkyl, C3 to C4 alkenyl, C1 to C4 alkoxy, halo, CN, CF3, OCF3, NO2, NHR11, NHCOR12, NHSO2R12, SO2R12, SO2NHR11, COR11, CO2R11;
R2 is C1 to C6 alkyl, C3 to C6 alkenyl or (CH2)n(C3 to C6 cycloalkyl) wherein n is 0, 1 or 2;
R13 is OR3 or NR5R6;
R3 is C1 to C6 alkyl optionally substituted with one or two substituents selected from C3 to C5 cycloalkyl, hydroxy, C1 to C4 alkoxy, benzyloxy, NR5R6, phenyl, Het1, Het2, Het3 or Het4 wherein the C1 to C6 alkyl and C1 to C4 alkoxy groups may optionally be terminated by a haloalkyl group such as CF3 and wherein the C3-C5 cycloalkyl group may optionally be substituted by C1-C4 alkyl, hydroxy or halo;
C3 to C6 cycloalkyl; Het1, Het2, Het3 or Het4;
R4 is a piperazin-1-ylsulphonyl group having a substituent R10 at the 4-position of the piperazinyl group wherein said piperazinyl group is optionally substituted with one or two C1 to C4 alkyl groups and is optionally in the form of its 4-N-oxide;
R5 and R8 are each independently selected from H and C1 to C4 alkyl optionally substituted with C3 to C5 cycloalkyl or C1 to C4 alkoxy, or, together with the nitrogen atom to which they are attached, form an azetidinyl, pyrrolidinyl, piperidinyl or morpholinyl group;
R7 and R8 are each independently selected from H, C1 to C4 alkyl, C3 to C4 alkenyl, CO2R9 or SO2R9;
R9 is C1 to C4 alkyl optionally substituted with C1 to C4 haloalkyl, C1 to C4 haloalkoxy or phenyl wherein said phenyl group is optionally substituted by one or more substituents selected from C1 to C4 alkyl optionally substituted by C1 to C4 haloalkyl or C1 to C4 haloalkoxy, C1 to C4 alkoxy, halo, CN, NO2, NHR11, NHCOR12, NHSO2R12, SO2R12, SO2NHR11, COR11 or CO2R11;
R10 is H; C1 to C4 alkyl optionally substituted with one or two substituents selected from hydroxy, NR5R6, CONR5R6, phenyl optionally substituted with C1 to C4 alkyl or C1 to C4 alkoxy; C3 to C6 alkenyl or Het4;
R11 is H, C1 to C4 alkyl, C3 to C4 alkenyl, CO(C1 to C4 alkyl) or C1 to C4 haloalkyl;
R12 is C1 to C4 alkyl, C3 to C4 alkenyl, C1 to C4 haloalkyl or C1 to C4 haloalkoxy;
Het1 is an N-linked 4-, 5- or 6-membered nitrogen-containing heterocyclic group optionally containing one or more further heteroatoms selected from S, N or O;
Het2 is a C-linked 5-membered heterocyclic group containing an O, S or N heteroatom optionally containing one or more heteroatoms selected from N, O or S;
Het3 is a C-linked 6-membered heterocyclic group containing an O or S heteroatom optionally containing one or more heteroatoms selected from O, S or N or Het3 is a C-linked 6-membered heterocyclic group containing three N heteroatoms;
Het4 is a C-linked 4-, 5- or 6-membered heterocyclic group containing one, two or three heteroatoms selected from S, O or N; and
wherein any of said heterocyclic groups Het1, Het2, Het3 or Het4 may be saturated, partially unsaturated or aromatic and wherein any of said heterocyclic groups may be optionally substituted with one or more substituents selected from C1 to C4 alkyl, C3 to C4 alkenyl, C1 to C4 alkoxy, halo, CF3, CO2R11, COR11, SO2R12, NHR11 or NHCOR12 and/or wherein any of said heterocyclic groups is benzo-fused;
with the provisos that (a) when R1 is C1 to C3 alkyl then Het1 is not morpholinyl or piperidinyl and (b) when R1 is C1 to C3 alkyl substituted by phenyl then said phenyl group is not substituted by C1 to C4 alkoxy, halo, CN, CF3, OCF3 or C1 to C4 alkyl.
As will be recognized by the skilled chemist, the general formula (I) can be represented by the regio-isomeric general formulae (IA) and (IB). Thus the present invention provides compounds of formulae (IA) and (IB): 
wherein R1, R2, R4 and R13 are as defined hereinbefore.
In the above definitions, unless otherwise indicated, alkyl, alkoxy and alkenyl groups having three or more carbon atoms, and alkanoyl groups having four or more carbon atoms, may be straight chain or branched chain. For example, a C4 alkyl substituent can be in the form of normal-butyl (n-butyl), iso-butyl (i-butyl), secondary-butyl (sec-butyl) or tertiary-butyl (t-butyl). The term halo atom includes Cl, Br, F, and I. Haloalkyl and haloalkoxy are preferably xe2x80x94CF3 and xe2x80x94OCF3 respectively. The term aromatic as defined herein means a fully unsaturated system.
A compound of the formula (I) contains one or more asymmetric carbon atoms and therefore exists in two or more stereoisomeric forms. Where a compound of the formula (I) contains an alkenyl or alkenylene group, cis (E) and trans (Z) isomerism may also occur. The present invention includes the individual stereoisomers of the compounds of the formula (I) and, where appropriate, the individual tautomeric forms thereof, together with mixtures thereof. Separation of diastereoisomers or cis and trans isomers may be achieved by conventional techniques, e.g. by fractional crystallisation, chromatography or H.P.L.C. of a stereoisomeric mixture of a compound of the formula (I) or a suitable salt or derivative thereof. An individual enantiomer of a compound of the formula (I) may also be prepared from a corresponding optically pure intermediate or by resolution, such as by H.P.L.C. of the corresponding racemate using a suitable chiral support or by fractional crystallisation of the diastereoisomeric salts formed by reaction of the corresponding racemate with a suitable optically active acid or base, as appropriate.
All stereoisomers are included within the scope of the invention.
The compounds of formulae (IA) and (IB) may also exist in tautomeric forms and the invention includes both mixtures thereof and the individual tautomers.
Also included in the invention are radiolabelled derivatives of compounds of formulae (I), (IA) and (IB) which are suitable for biological studies.
The pharmaceutically or veterinarily acceptable salts of the compounds of the invention which contain a basic centre are, for example, non-toxic acid addition salts formed with inorganic acids such as hydrochloric, hydrobromic, hydroiodic, sulphuric and phosphoric acid, with carboxylic acids or with organo-sulphonic acids. Examples include the HCl, HBr, Hl, sulphate or bisulphate, nitrate, phosphate or hydrogen phosphate, acetate, benzoate, succinate, saccarate, fumarate, maleate, lactate, citrate, tartrate, gluconate, camsylate, methanesulphonate, ethanesulphonate, benzenesulphonate, p-toluenesulphonate and pamoate salts. Compounds of the invention can also provide pharmaceutically or veterinarily acceptable metal salts, in particular non-toxic alkali and alkaline earth metal salts, with bases. Examples include the sodium, potassium, aluminium, calcium, magnesium, zinc and diethanolamine salts. For a review on suitable pharmaceutical salts see Berge et al, J. Pharm, Sci., 66, 1-19, 1977.
The pharmaceutically acceptable solvates of the compounds of the invention include the hydrates thereof.
Also included within the scope of the compound and various salts of the invention are polymorphs thereof.
A preferred group of compounds of formulae (I), (IA) and (IB) is that wherein, R1 is C1 to C6 alkyl or C3 to C6 alkenyl wherein said alkyl or alkenyl groups may be branched chain or straight chain or R1 is C3 to C6 cycloalkyl or C4 to C6 cycloalkenyl
and wherein when R1 is C1 to C3 alkyl said alkyl group is substituted by; and
wherein when R1 is C4 to C6 alkyl, C3 to C6 alkenyl, C3 to C6 cycloalkyl or C4 to C6 cycloalkenyl said alkyl, alkenyl, cycloalkyl or cycloalkenyl group is optionally substituted by;
one or more substituents selected from:
hydroxy;
C1 to C4 alkoxy;
C3 to C4 cycloalkyl;
phenyl substituted with one or more substitutents selected from C1 to C3 alkyl, C1 to C4 alkoxy, C1 to C4 haloalkyl or C1 to C4 haloalkoxy, halo, CN, NO2, NHR1, NHCOR , NHSO2R12, SO2R12, SO2NHR11, COR11, CO2R wherein said haloalkyl and haloalkoxy groups contain one or more halo atoms;
NR7R8, CONR7R8 or NR7COR11;
a Het1 group which is an N-linked 4-membered N-containing heterocyclic group;
a Het2 group which is a C-linked 5-membered heterocyclic group containing an O, S or N heteroatom optionally containing one or more heteroatoms selected from N, O or S;
a Het3 group which is a C-linked 6-membered heterocyclic group containing an O or S heteroatom optionally containing one or more heteroatoms selected from O, S or N or a Het3 group which is a C-linked 6-membered heterocyclic group containing three N heteroatoms;
wherein R7, R8, R11 and R12 are as previously defined herein
or R1 is a Het group which is a C-linked 4- or 5-membered heterocyclic group containing one heteroatom selected from S, O or N; a Het4 group which is a C-linked 6-membered heterocyclic group containing one, two or three heteroatoms selected from S or O; a Het4 group which is a C-linked 6-membered heterocyclic group containing three nitrogen heteroatoms; a Het4 group which is a C-linked 6-membered heterocyclic group containing one or two nitrogen heteroatoms which is substituted by one or more substitutents selected from C1 to C4 alkyl, C1 to C4 alkoxy, CO2R11, SO2R 2, COR11, NHR11 or NHCOR12 and optionally including a further heteroatom selected from S, O or N
wherein any of said heterocyclic groups Het1, Het2, Het3 or Het4 is saturated, partially unsaturated or aromatic as appropriate and wherein any of said heterocyclic groups is optionally substituted with one or more substituents selected from C1 to C4 alkyl, C3 to C4 alkenyl, C1 to C4 alkoxy, halo, CO2R11, SO2R12, COR11 or NHR11 wherein R11 is as defined hereinbefore and/or wherein any of said heterocyclic groups is benzo-fused;
or R1 is phenyl substituted by one or more substituents selected from CF3, OCF3, SO2R12 or CO2R12 wherein R12 is C1 to C4 alkyl which is optionally substituted by phenyl, C1 to C4 haloalkyl or C1 to C4 haloalkoxy wherein said haloalkyl and haloalkoxy groups contain one or more halo atoms;
R2 is C1 to C6 alkyl;
R13 is OR3;
R3 is C1 to C6 alkyl optionally substituted with one or two substituents selected from C3 to C5 cycloalkyl, hydroxy, C1 to C4 alkoxy, benzyloxy, NR5R6, phenyl, furanyl, tetrahydrofuranyl or pyridinyl wherein said C1 to C6 alkyl and C1 to C4 alkoxy groups may optionally be terminated by a haloalkyl group such as CF3;
or R3 is C3 to C6 cycloalkyl, 1-(C1 to C4 alkyl)piperidinyl, tetrahydrofuranyl or tetrahydropyranyl;
R4 is a piperazin-1-ylsulphonyl group having a substituent R10 at the 4-position of the piperazinyl group wherein said piperazinyl group is optionally substituted with one or two C1 to C4 alkyl groups and is optionally in the form of its 4-N-oxide;
R5 and R6 are each independently selected from H and C1 to C4 alkyl optionally substituted with C3 to C5 cycloalkyl or C1 to C4 alkoxy, or, together with the nitrogen atom to which they are attached, form an azetidinyl, pyrrolidinyl, piperidinyl or morpholinyl group; and
R10 is H; C1 to C4 alkyl optionally substituted with one or two substituents selected from hydroxy, NR5R6, CONR5R6, phenyl optionally substituted with C1 to C4 alkyl or C1 to C4 alkoxy; C3 to C6 alkenyl; Het4;
with the proviso that when R1 is C1 to C3 alkyl substituted by phenyl then said phenyl group is not substituted by C1 to C4 alkoxy; CN; halo; CF3; OCF3; or C1 to C4 alkyl.
A further preferred group of compounds of formulae (I), (IA) and (IB) is that wherein, R1 is C1 to C6 alkyl wherein said alkyl may be branched or straight chain or R1 is C3 to C6 cycloalkyl
and wherein when R1 is C1 to C3 alkyl said alkyl group is substituted by; and
wherein when R1 is C4 to C6 alkyl or C3 to C6 cycloalkyl said alkyl or cycloalkyl group is optionally substituted by;
one or more substituents selected from:
hydroxy;
C1 to C2 alkoxy;
C3 to C5 cycloalkyl;
NR7R3, NR7COR11 or COR11 wherein R7 and R8 are each independently selected from H, C1 to C4 alkyl or CO2R9 wherein R9 and R11 are as previously defined herein;
a Het1 group which is an N-linked 4-membered N-containing heterocyclic group;
a Het3 group which is a C-linked 6-membered heterocyclic group containing an O or S heteroatom optionally containing one or more heteroatoms selected from O, S or N or a Het3 group which is a C-linked 6-membered heterocyclic group containing three N heteroatoms;
or R1 is a Het4 group which is a C-linked 4-membered heterocyclic group containing one heteroatom selected from S, O or N or R1 is a Het4 group which is a C-linked 6-membered heterocyclic group containing one, two or three heteroatoms selected from S or O
wherein any of said heterocyclic groups Het1, Het2, Het3 or Het4 is saturated, partially unsaturated or aromatic and is optionally substituted with one or more substituents selected from C1 to C4 alkyl, C1 to C4 alkoxy, xe2x80x94CO2R11, xe2x80x94SO2R12 xe2x80x94COR11 or NHR11 wherein R11 and R12 are as defined hereinbefore and/or wherein any of said heterocyclic groups is benzo-fused;
or R1 is phenyl substituted by one or more substituents selected from: CF3, xe2x80x94OCF3, xe2x80x94SO2R12, xe2x80x94COR11, CO2R11 wherein R11 and R12 are as defined hereinbefore;
R2 is C1 to C6 alkyl;
R13 is OR3;
R3 is methyl, ethyl, n-propyl, i-propyl, n-butyl, sec-butyl, i-butyl or t-butyl alkyl optionally substituted with one or two substituents selected from cyclopropyl, cyclobutyl, hydroxy, methoxy, ethoxy, benzyloxy, phenyl, benzyl, furan-3-yl, tetrahydrofuran-2-ylmethyl, tetrahydrofuran-3-ylmethyl, pyridin-2-yl, pyridin-3-yl or NR5R6 wherein R5 and R6 are each independently selected from H and C1 to C2 alkyl;
R4 is a piperazin-1-ylsulphonyl group having a substituent, R10 at the 4-position of the piperazinyl group wherein said piperazinyl group is optionally substituted with one or two C1 to C4 alkyl groups and is optionally in the form of its 4-N-oxide; and
R10 is H, C1 to C3 alkyl optionally substituted with one or two substituents selected from hydroxy, NR5R6, CONR5R6 wherein R5 and R6 are each independently selected from H, C1 to C4 alkyl and C3 alkenyl.
Preferred compounds of the present invention include:
5-[2-Ethoxy-5-(4-methylpiperazin-1 -ylsulphonyl)pyridin-3-yl]-2-[2-methoxyethyl]-3-n-propyl-2,6-dihydro-7H-pyrazolo[4,3-d]pyrimidin-7-one, 5-[2-Ethoxy-5-(4-methylpiperazin-1 -ylsulphonyl)pyridin-3-yl]-3-ethyl-2-[2-methoxyethyl]-2,6-dihydro-7H-pyrazolo[4,3-d]pyrimidin-7-one, 5-[2-Ethoxy-5-(4-ethylpiperazin-1 -ylsulphonyl)pyridin-3-yl]-2-[2-methoxyethyl]-3-n-propyl-2,6-dihydro-7H-pyrazolo[4,3-d]pyrimidin-7-one, 2-(sec-Butyl)-5-[2-ethoxy-5-(4-ethylpiperazin- 1 -ylsulphonyl)pyridin-3-yl]-3-ethyl-2,6-dihydro-7H-pyrazolo[4,3-d]pyrimidin-7-one, 2-(iso-Butyl)-5-[2-ethoxy-5-(4-ethylpiperazin-1 -ylsulphonyl)pyridin-3-yl]-3-ethyl-2,6-dihydro-7H-pyrazolo[4,3-d]pyrimidin-7-one, 2-(Cyclopropylmethyl)-5-[2-ethoxy-5-(4-ethylpiperazin-1 -ylsulphonyl)pyridin-3-yl]-3-ethyl-2,6-dihydro-7H-pyrazolo[4,3-d]pyrimidin-7-one, 2-(Cyclobutylmethyl)-5-[2-ethoxy-5-(4-ethylpiperazin-1 -ylsulphonyl)pyridin-3-yl]-3-ethyl-2,6-dihydro-7H-pyrazolo[4,3-d]pyrimidin-7-one, 5-[2-Ethoxy-5-(4-ethylpiperazin-1 -ylsulphonyl)pyridin-3-yl]-3-ethyl-2-[2-methoxyethyl]-2,6-dihydro-7H-pyrazolo[4,3-d]pyrimidin-7-one, 5-[2-Ethoxy-5-(4-ethylpiperazin-1 -ylsulphonyl)pyridin-3-yl]-3-ethyl-2-[2-methoxy-1 -methylethyl]-2,6-dihydro-7H-pyrazolo[4,3-d]pyrimidin-7-one, 5-[2-Ethoxy-5-(4-ethylpiperazin-1 -ylsulphonyl)pyridin-3-yl]-3-ethyl-2-[2-(methylamino)ethyl]-2,6-dihydro-7H-pyrazolo[4,3-d]pyrimidin-7-one, 2-(2-Dimethylaminoethyl)-5-[2-ethoxy-5-(4-ethylpiperazin-1-ylsulphonyl)pyridin-3-yl]-3-ethyl-2,6-dihydro-7H-pyrazolo[4,3-d]pyrimidin-7-one, 5-[2-Ethoxy-5-(4-ethylpiperazin-1 -ylsulphonyl)pyridin-3-yl]-3-ethyl-2-(1-methylazetidin-3-yl)-2,6-dihydro-7H-pyrazolo[4,3-d]pyrimidin-7-one, 5-[2-n-Butoxy-5-(4-ethylpiperazin-1 -ylsulphonyl)pyridin-3-yl]-2-dimethylaminoethyl-3-ethyl-2,6-dihydro-7H-pyrazolo[4,3-d]pyrimidin-7-one, 5-[2-Ethoxy-5-(4-ethylpiperazin-1 -ylsulphonyl)pyridin-3-yl]-3-ethyl-2-(1-ethylazetidin-3-yl)-2,6-dihydro-7H-pyrazolo[4,3-d]pyrimidin-7-one, 2-{2-[Acetyl(methyl)amino]ethyl}-5-[5-(4-ethylpiperazin-1 -ylsulphonyl)-2-n-propoxypyridin-3-yl]-3-ethyl-2,6-dihydro-7H-pyrazolo[4,3-d]pyrimidin-7-one, 2-(1 -Acetylazetidin-3-yl)-5-[2-n-butoxy-5-(4-ethylpiperazin-1-ylsulphonyl)pyridin-3-yl]-3-ethyl-2,6-dihydro-7H-pyrazolo[4,3-d]pyrimidin-7-one, 5-[2-iso-Butoxy-5-(4-ethylpiperazin-1 -ylsulphonyl)pyridin-3-yl]-2-(2-methoxyethyl)-3-n-propyl-2,6-dihydro-7H-pyrazolo[4,3-d]pyrimidin-7-one, 5-[2-n-Butoxy-5-(4-ethylpiperazin- 1 -ylsulphonyl)pyridin-3-yl]-3-ethyl-2-(2-methoxyethyl)-2,6-dihydro-7H-pyrazolo[4,3-d]pyrimidin-7-one, 3-Ethyl-5-[5-(4-ethylpiperazin-1 -ylsulphonyl)-2-(2-methoxyethoxy)pyridin-3-yl]-2-(2-methoxyethyl)-2,6-dihydro-7H-pyrazolo[4,3-d]pyrimidin-7-one, 5-[2-n-Butoxy-5-(4-ethylpiperazin-1 -ylsulphonyl)pyridin-3-yl]-3-ethyl-2-(1-methylazetidin-3-yl)-2,6-dihydro-7H-pyrazolo[4,3-d]pyrimidin-7-one, 5-[2-n-Butoxy-5-(4-ethylpiperazin- 1 -ylsulphonyl)pyridin-3-yl]-3-ethyl-2-(1-ethylazetidin-3-yl)-2,6-dihydro-7H-pyrazolo[4,3-d]pyrimidin-7-one, 5-[2-Benzyloxy-5-(4-ethylpiperazin-1 -ylsulphonyl)pyridin-3-yl]-3-ethyl-2-(1-ethylazetidin-3-yl)-2,6-dihydro-7H-pyrazolo[4,3-d]pyrimidin-7-one, 5-[2-iso-Butoxy-5-(4-methylpiperazin-1 -ylsulphonyl)pyridin-3-yl]-3-ethyl-2-(2-methoxyethyl)-2,6-dihydro-7H-pyrazolo[4,3-d]pyrimidin-7-one, 3-Ethyl-5-[5-(4-ethylpiperazin-1 -ylsulphonyl)-2-n-propoxypyridin-3-yl]-2-(2-methoxyethyl)-2,6-dihydro-7H-pyrazolo[4,3-d]pyrimidin-7-one, 5-[2-n-Butoxy-5-(4-ethylpiperazin-1 -ylsulphonyl)pyridin-3-yl]-3-ethyl-2-(2-methoxyethyl)-2,6-dihydro-7H-pyrazolo[4,3-d]pyrimidin-7-one, 3-Ethyl-5-[5-(4-ethylpiperazin-1 -ylsulphonyl)-2-iso-propoxypyridin-3-yl]-2-(2-methoxyethyl)-2,6-dihydro-7H-pyrazolo[4,3-d]pyrimidin-7-one, 5-[(S)-2-sec-Butoxy-5-(4-ethylpiperazin-1 -ylsulphonyl)pyridin-3-yl]-3-ethyl-2-(2-methoxyethyl)-2,6-dihydro-7H-pyrazolo[4,3-d]pyrimidin-7-one, 5-[(R)-2-sec-Butoxy-5-(4-ethylpiperazin-1 -ylsulphonyl)pyridin-3-yl]-3-ethyl-2-(2-methoxyethyl)-2,6-dihydro-7H-pyrazolo[4,3-d]pyrimidin-7-one, 3-Ethyl-5-[5-(4-ethylpiperazin-1 -ylsulphonyl)-2-{(pyridin-2-yl)methyl}pyridin-3-yl]-2-(2-methoxyethyl)-2,6-dihydro-7H-pyrazolo[4,3-d]pyrimidin-7-one, 2-sec-Butyl-3-ethyl-5-[5-(4-ethylpiperazin-1 -ylsulphonyl)-2-(2-methoxyethoxy)pyridin-3-yl]-2,6-dihydro-7H-pyrazolo[4,3-d]pyrimidin-7-one, 2-Cyclobutylmethyl-3-ethyl-5-[5-(4-ethylpiperazin-1 -ylsulphonyl)-2-(2-methoxyethoxy)pyridin-3-yl]-2,6-dihydro-7H-pyrazolo[4,3-d]pyrimidin-7-one, 3-Ethyl-5-[5-(4-ethylpiperazin-1 -ylsulphonyl)-2-(S)-(2-methoxy-1-methylethoxy)pyridin-3-yl]-2-(2-methoxyethyl)-2,6-dihydro-7H-pyrazolo[4,3-d]pyrimidin-7-one, 3-Ethyl-5-[5-(4-ethylpiperazin-1 -ylsulphonyl)-2-(R)-(2-methoxy-1-methylethoxy)pyridin-3-yl]-2-(2-methoxyethyl)-2,6-dihydro-7H-pyrazolo[4,3-d]pyrimidin-7-one, 5-[5-(4-Ethylpiperazin-1-ylsulphonyl)-2-(S)-(2-methoxy-1-methylethoxy)pyridin-3-yl]-2-(2-methoxyethyl)-3-n-propyl-2 ,6-dihydro-7H-pyrazolo[4,3-d]pyrimidin-7-one, 5-[5-(4-Ethylpiperazin-1-ylsulphonyl)-2-(R)-(2-methoxy-1-methylethoxy)pyridin-3-yl]-2-(2-methoxyethyl)-3-n-propyl-2,6-dihydro-7H-pyrazolo[4,3-d]pyrimidin-7-one, 5-[2-Ethoxy-5-(4-ethylpiperazin-1-ylsulphonyl)pyridin-3-yl]-3-ethyl-2-(2-hydroxyethyl)-2,6-dihydro-7H-pyrazolo[4,3-d]pyrimidin-7-one, 2-(2-Dimethylaminoethyl)-5-[2-ethoxy-5-(4-ethylpiperazin-1-ylsulphonyl)pyridin-3-yl]-3-ethyl-2,6-dihydro-7H-pyrazolo[4,3-d]pyrimidin-7-one, 2-iso-Butyl-3-ethyl-5-[2-(2-methoxyethoxy)-5-(4-methylpiperazin-1-ylsulphonyl)pyridin-3-yl]-2,6-dihydro-7H-pyrazolo[4,3-d]pyrimidin-7-one, 2-iso-Butyl-3-ethyl-5-[5-(4-ethylpiperazin-1-ylsulphonyl)-2-(2-methoxyethoxy)pyridin-3-yl]-2,6-dihydro-7H-pyrazolo[4,3-d]pyrimidin-7-one, 2-Cyclobutylmethyl-3-ethyl-5-[2-(2-methoxyethoxy)-5-(4-methylpiperazin-1-ylsulphonyl)pyridin-3-yl]-2,6-dihydro-7H-pyrazolo[4,3-d]pyrimidin-7-one, 5-[2-n-Butoxy-5-(4-ethylpiperazin-1-ylsulphonyl)pyridin-3-yl]-2-[2-(dimethylamino)-2-oxoethyl]-3-ethyl-2,6-dihydro-7H-pyrazolo[4,3-d]pyrimidin-7-one, 5-[2-n-Butoxy-5-(4-ethylpiperazin-1-ylsulphonyl)pyridin-3-yl]-3-ethyl-2-{2-[methyl(methylsulphonyl)amino]ethyl}-2,6-dihydro-7H-pyrazolo[4,3-d]pyrimidin-7-one, 2-Cyclobutylpropylmethyl-3-ethyl-5-[2-(2-methoxyethoxy)-5-(4-methylpiperazin-1-ylsulphonyl)pyridin-3-yl]-2,6-dihydro-7H-pyrazolo[4,3-d]pyrimidin-7-one, 2-n-Butyl-3-ethyl-5-[2-(2-methoxyethoxy)-5-(4-methylpiperazin-1-ylsulphonyl)pyridin-3-yl]-2,6-dihydro-7H-pyrazolo[4,3-d]pyrimidin-7-one, 5-[2-n-Butoxy-5-(4-methylpiperazin-1-ylsulphonyl)pyridin-3-yl)-3-ethyl-2-(2-methoxyethyl)-2,6-dihydro-7H-pyrazolo[4,3-d]pyrimidin-7-one, 2-(2-Ethoxyethyl)-3-ethyl-5-(5-(4-ethylpiperazin-1-ylsulphonyl)-2-(2-methoxyethoxy)pyridin-3-yl]-2 ,6-dihydro-7H-pyrazolo[4,3-d]pyrimidin-7-one, 5-[2-Ethoxy-5-(4-ethylpiperazin-1-ylsulphonyl)pyridin-3-yl]-3-ethyl-2-(3-methoxypropyl)-2 ,6-dihydro-7H-pyrazolo[4,3-d]pyrimidin-7-one, 5-[2-Ethoxy-5-(4-ethylpiperazin-1-ylsulphonyl)pyridin-3-yl]-3-ethyl-2-(S)-(2-methoxypropyl)-2,6-dihydro-7H-pyrazolo[4,3-d]pyrimidin-7-one, 5-[2-Ethoxy-5-(4-ethylpiperazin-1-ylsulphonyl)pyridin-3-yl]-3-ethyl-2-(R)-(2-methoxypropyl)-2,6-dihydro-7H-pyrazolo[4,3-d]pyrimidin-7-one, 2-(S)-sec-Butyl-3-ethyl-5-[5-(4-ethylpiperazin-1-ylsulphonyl)-2-(2-methoxyethoxy)pyridin-3-yl]-2,6-dihydro-7H-pyrazolo[4,3-d]pyrimidin-7-one, 5-[2-Ethoxy-5-(4-ethylpiperazin-1-ylsulphonyl)pyridin-3-yl]-3-ethyl-1-(2-methoxyethyl)-1,6-dihydro-7H-pyrazolo[4,3-d]pyrimidin-7-one, 2-(R)-sec-Butyl-3-ethyl-5-[5-(4-ethylpiperazin-1-ylsulphonyl)-2-(2-methoxyethoxy)pyridin-3-yl]-2,6-dihydro-7H-pyrazolo[4,3-d]pyrimidin-7-one, 2-Cyclobutyl-5-[2-ethoxy-5-(4-ethylpiperazin-1-ylsulphonyl)pyridin-3-yl]-3-ethyl-2,6-dihydro-7H-pyrazolo[4,3-d]pyrimidin-7-one, 2-Cyclopentyl-5-[2-ethoxy-5-(4-ethylpiperazin-1-ylsulphonyl)pyridin-3-yl]-3-ethyl-2,6-dihydro-7H-pyrazolo[4,3-d]pyrimidin-7-one, 2-Cyclopentylmethyl-5-[2-ethoxy-5-(4-ethylpiperazin-1-ylsulphonyl)pyridin-3-yl]-3-ethyl-2,6-dihydro-7H-pyrazolo[4,3-d]pyrimidin-7-one, 2-Cyclohexyl-5-[2-ethoxy-5-(4-ethylpiperazin-1-ylsulphonyl)pyridin-3-yl]-3-ethyl-2,6-dihydro-7H-pyrazolo[4,3-d]pyrimidin-7-one, 5-[2-Ethoxy-5-(4-ethylpiperazin-1-ylsulphonyl)pyridin-3-yl]-2-(2-ethoxyethyl)-3-ethyl-2,6-dihydro-7H-pyrazolo[4,3-d]pyrimidin-7-one, 5-[2-Ethoxy-5-(4-ethylpiperazin-1-ylsulphonyl)pyridin-3-yl]-3-ethyl-2-[(1S)-1-methyl-2-methoxyethyl)-2,6-dihydro-7H-pyrazolo[4,3-d]pyrimidin-7-one, 5-[2-Ethoxy-5-(4-ethylpiperazin-1-ylsulphonyl)pyridin-3-yl]-3-ethyl-2-[(1R)-1-methyl-2-methoxyethyl]-2,6-dihydro-7H-pyrazolo[4,3-d]pyrimidin-7-one, 5-[2-Ethoxy-5-(4-ethylpiperazin-1-ylsulphonyl)pyridin-3-yl]-3-ethyl-2-(3-methoxy-n-propyl)-2,6-dihydro-7H-pyrazolo[4,3-d]pyrimidin-7-one, 2-Cyclobutyl-3-ethyl-5-[5-(4-ethylpiperazin-1-ylsulphonyl)-2-(2-methoxyethoxy)pyridin-3-yl]-2,6-dihydro-7H-pyrazolo[4,3-d]pyrimidin-7-one, 5-[2-n-Butoxy-5-(4-methylpiperazin-1-ylsulphonyl)pyridin-3-yl]-3-ethyl-2-(2-methoxyethyl)-2,6-dihydro-7H-pyrazolo[4,3-d]pyrimidinone, 3-Ethyl-5-(2-(2-methoxyethoxy)-5-(4-methylpiperazin-1-ylsulphonyl)pyridin-3-yl]-2-[(1S)-1-methylpropyl]-2,6-dihydro-7H-pyrazolo[4,3-d]pyrimidinone, 3-Ethyl-5-[2-(2-methoxyethoxy)-5-(4-methylpiperazin-1-ylsulphonyl)pyridin-3-yl]-2-[(1R)-1-methylpropyl]-2,6-dihydro-7H-pyrazolo[4,3-d]pyrimidinone, 2-n-Butyl-3-ethyl-5-[2-(2-methoxyethoxy)-5-(4-methylpiperazin-1-ylsulphonyl)pyridin-3-yl]-2,6-dihydro-7H-pyrazolo[4,3-d]pyrimidinone, 2-Cyclopropylmethyl-3-ethyl-5-[2-(2-methoxyethoxy)-5-(4-methylpiperazin-1-ylsulphonyl)pyridin-3-yl]-2,6-dihydro-7H-pyrazolo[4,3-d]pyrimidinone, 2-Cyclobutylmethyl-3-ethyl-5-[5-(4-ethylpiperazin-1-ylsulphonyl)-2-(tetrahydro-2-furanylmethoxy)pyridin-3-yl]-2,6-dihydro-7H-pyrazolo[4,3-d]pyrimidinone, 3-Ethyl-5-[5-(4-ethylpiperazin-1-ylsulphonyl)-2-(2-methoxyethoxy)pyridin-3-yl]-2-(2-methoxyethoxy)-2,6-dihydro-7H-pyrazolo[4,3-d]pyrimidinone, 5-[2-Ethoxy-5-(4-isopropylpiperazin-1-ylsulphonyl)pyridin-3-yl]-3-ethyl-2-(2-methoxyethyl)-2,6-dihydro-7H-pyrazolo[4,3-d]pyrimidinone and 5-[2-Ethoxy-5-(4-n-propylpiperazin-1-ylsulphonyl)pyridin-3-yl]-3-ethyl-2-(2-methoxyethyl)-2,6-dihydro-7H-pyrazolo[4,3-d]pyrimidinone.
A yet further preferred group of compounds of formulae (I), (IA) or (IB) is that wherein
R1 is xe2x80x94(CH2)n(C3-C6)cycloalkyl wherein n is 0, 1, 2 or 3; or
R1 is methyl, ethyl, iso-propyl or n-propyl substituted by one or more C1 to C4 alkoxy substituents wherein said alkoxy substituent may be directly attached to any C-atom within the ethyl, iso-propyl or n-propyl groups other than the C-atom directly linked to the pyrazole ring; or
R1 is a C4 alkyl group selected from i-, n-, sec- or t-butyl optionally substituted by one or more substituents selected from C1 to C4 alkoxy or C3 to C4 cycloalkyl;
R2 is C1 to C4 alkyl;
R13 is OR3 wherein R3 is C1 to C4 alkyl optionally substituted with one or two C1 to C4 alkoxy substituents wherein said C1 to C4 alkyl and C1 to C4 alkoxy groups may optionally be terminated by a haloalkyl group such as CF3;
R4 is a piperazin-1-ylsulphonyl group having a single substituent, R10 at the 4-position of the piperazinyl group and is optionally in the form of its 4-N-oxide;
and R10 is methyl, ethyl, n-propyl or i-propyl.
A particularly preferred group of compounds of formulae (I), (IA) or (IB) is that wherein
R1 is xe2x80x94(CH2)n(C3-C4)cycloalkyl wherein n is 1 or 2; or
R1 is xe2x80x94(CH2)n(C3-C6)cycloalkyl wherein n is 0; or
R1 is -cyclopentyl methyl; or
R1 is methyl, ethyl, i-propyl or n-propyl substituted by methoxy, ethoxy, n-propoxy or i-propoxy wherein said alkoxy substituent may be directly attached to any C-atom within the ethyl, iso-propyl or n-propyl groups other than the C-atom directly linked to the pyrazole ring; or
R1 is i-, n-, sec- or t-butyl;
R2 is C2 to C4 alkyl;
R13 is OR3 wherein the R3 alkyl group is methyl, ethyl, n-propyl, i-propyl, i-butyl, n-butyl, sec-butyl or t-butyl optionally substituted with one or two methoxy, ethoxy, n-propoxy or i-propoxy substituents; and R4 is a 4-methyl, 4-ethyl, 4-n-propyl or 4-i-propylpiperazin-1-ylsulphonyl group.
In highly preferred embodiment of the present invention there is provided a compound of the formula (IB) wherein
R1 is xe2x80x94(CH2)n(C3-C4)cycloalkyl wherein n is 1 or 2; or R1 is xe2x80x94(CH2)n(C3-C5)cycloalkyl wherein n is 0; or R1 is -cyclopentylmethyl; or R1 is methyl, ethyl, i-propyl or n-propyl substituted by methoxy, ethoxy, n-propoxy or i-propoxy wherein said alkoxy substituent may be directly attached to any C-atom within the ethyl, iso-propyl or n-propyl groups other than the C-atom directly linked to the pyrazole ring; or
R1 is i-, n-, sec- or t-butyl;
R2 is C2 to C4 alkyl; R13 is OR3 wherein the R3 alkyl group is methyl, ethyl, n-propyl, i-propyl, i- butyl, n- butyl, sec-butyl or t-butyl; and R4 is a 4-methyl or 4-ethylpiperazin-1-ylsulphonyl group.
Highly preferred compounds according to the present invention include: 1-{6-ethoxy-5-[3-ethyl-6,7-dihydro-2-(2-methoxyethyl)-7-oxo-2H-pyrazolo[4,3-d]pyrimidin-5-yl]-3-pyridylsulfonyl}-4-ethylpiperazine and salts and polymorphs thereof. Preferred salts of 1-{6-ethoxy-5-[3-ethyl-6,7-dihydro-2-(2-methoxyethyl)-7-oxo-2H-pyrazolo[4,3- d]pyrimidin-5-yl]-3-pyridylsulfonyl}-4-ethylpiperazine are sulphonic acid salts, more preferably the p-toluenesulfonate, benzenesulfonate, camphorsulfonate and ethanesulfonate salts respectively, and especially the benzenesulfonate.
According to a further aspect of the present invention there are provided compounds of the general formula (I): 
or a pharmaceutically or veterinarily acceptable salt thereof, or a pharmaceutically or veterinarily acceptable solvate of either entity, wherein
R1 is C1 to C6 alkyl or C3 to C6 alkenyl, C3 to C6 cycloalkyl or C3 to C6 cycloalkenyl wherein said alkyl group may be branched or straight chain and wherein
when R1 is C1 to C3 alkyl said alkyl group is substituted by; and wherein
when R1 is C4 to C6 alkyl, C3 to C6 alkenyl or C3 to C6 cycloalkyl said alkyl, alkenyl or cycloalkyl group is optionally substituted by; one or more substituents selected from: hydroxy; C1 to C4 alkoxy; C3 to C6 cycloalkyl;
phenyl substituted with one or more substitutents selected from C1 to C3 alkyl, C1 to C4 alkoxy, C1 to C4 haloalkyl or C1 to C4 haloalkoxy wherein said haloalkyl and haloalkoxy groups contain one or more halo atoms, halo, CN, NO2, NHR11, NHSO2R12, SO2R12, SO2NHR11, COR11, CO2R11 wherein R11 is H, C1 to C4 alkyl, C2 to C4 alkenyl, C1 to C4 alkanoyl, C1 to C4 haloalkyl or C1 to C4 haloalkoxy and wherein R12 is C1 to C4 alkyl, C2 to C4 alkenyl, C1 to C4 alkanoyl, C1 to C4 haloalkyl or C1 to C4 haloalkoxy; NR7R8, CONR7R8 or NR 7COR11 wherein R7 and R8 are each independently selected from H, C1 to C4 alkyl, C2 to C4 alkenyl, C1 to C4 alkoxy, CO2R9, SO2R9 wherein said alkyl, alkenyl or alkoxy groups are optionally substituted by C1 to C4 haloalkyl or C1 to C4 haloalkoxy and wherein R9 is C1 to C4 alkyl which is optionally substituted with phenyl wherein said phenyl group is optionally substituted by one or more substituents selected from C1 to C4 alkyl optionally substituted by C1 to C4 haloalkyl or C1 to C4 haloalkoxy, C1 to C4 alkoxy, halo, CN, NO2, NHR11, NHSO2R12, SO2R12, SO2NHR1, COR11 or CO2R11; Het1; Het2 or Het3; or R1 is Het4 or phenyl wherein said phenyl group is optionally substituted by one or more substituents selected from C1 to C4 alkyl, C2 to C4 alkenyl, C1 to C4 alkoxy, halo, CN, CF3, OCF3, NO2, NHR11, NHSO2R12, SO2R12, SO2NHR11, COR11, CO2R11;
R2 is C1 to C6 alkyl, C3 to C6 alkenyl or (CH2)n(C3 to C6 cycloalkyl) wherein n is 0, 1 or 2;
R13is OR3 NR5R6;
R3 is OR3 or NR5R6;
R3 is C1 to C6 alkyl optionally substituted with one or two substituents selected from C3 to C5 cycloalkyl, hydroxy, C1 to C4 alkoxy, benzyloxy, NR5R6, phenyl, Het1, Het2, Het3 or Het4 wherein the C1 to C6 alkyl and C1 to C4 alkoxy groups may optionally be terminated by a haloalkyl group such as CF3; C3 to C6 cycloalkyl; Het1, Het2, Het3 or Het4;
R4 is a piperazin-1-ylsulphonyl group having a substituent, R10 at the 4-position of the piperazinyl group wherein said piperazinyl group is optionally substituted with one or two C1 to C4 alkyl groups and is optionally in the form of its 4-N-oxide;
R5 and R6 are each independently selected from H and C1 to C4 alkyl optionally substituted with C3 to C5 cycloalkyl or C1 to C4 alkoxy, or, together with the nitrogen atom to which they are attached, form an azetidinyl, pyrrolidinyl, piperidinyl or morpholinyl group;
R10 is H; C1 to C4 alkyl optionally substituted with one or two substituents selected from hydroxy, NR5R6, CONR5R6, phenyl optionally substituted with C1 to C4 alkyl or C1 to C4 alkoxy; C2 to C6 alkenyl or Het4;
Het1 is an N-linked 4-, 5- or 6-membered nitrogen-containing heterocyclic group optionally containing one or more further heteroatoms selected from S, N or O;
Het2 is a C-linked 5-membered heterocyclic group containing an O, S or N heteroatom optionally containing one or more heteroatoms selected from O or S;
Het3 is a C-linked 6-membered heterocyclic group containing an O or S heteroatom optionally containing one or more heteroatoms selected from O, S or N or Het3 is a C-linked 6-membered heterocyclic group containing three N heteroatoms;
Het4 is a C-linked 4-, 5- or 6-membered heterocyclic group containing one, two or three heteroatoms selected from S, O or N; and
wherein any of said heterocyclic groups Het1, Het2, Het3 or Het4 may be saturated, partially unsaturated or aromatic and wherein any of said heterocyclic groups may be optionally substituted with one or more substituents selected from C1 to C4 alkyl, C2 to C4 alkenyl, C1 to C4 alkoxy, halo, CO2R11, COR11, SO2R12 or NHR11 and/or wherein any of said heterocyclic groups is benzo-fused;
with the provisos that (a) when R1 is C1 to C3 then Het1 is not morpholinyl or piperidinyl and (b) when R1 is C1 to C3 substituted by phenyl then said phenyl group is not substituted by C1 to C4 alkoxy, halo, CN, CF3, OCF3 or C1 to C4 alkyl.
In a further aspect, the present invention provides processes for the preparation of compounds of formulae (I), (IA) and (IB), their pharmaceutically and veterinarily acceptable salts, and pharmaceutically and veterinarily acceptable solvates of either entity, as illustrated below. It will be appreciated by persons skilled in the art that, within certain of the processes described, the order of the synthetic steps employed may be varied and will depend inter alia on factors such as the nature of other functional groups present in a particular substrate, the availability of key intermediates and the protecting group strategy (if any) to be adopted. Clearly, such factors will also influence the choice of reagent for use in the said synthetic steps. Illustrative of a protecting group strategy is the route to the azetidine analogues (Examples 18, 19 and 20), the precursor to which (preparations 63, 66 and 61 respectively) contain t-butoxycarbonyl (Boc) as the nitrogen protecting group.
It will also be appreciated that various standard substituent or functional group interconversions and transformations within certain compounds of formulae (I), (IA) or (IB) will provide other compounds of formulae (I), (IA) or (IB). Examples include alkoxide exchange at the 2-position of the 5-(pyridin-3-yl) substituent (see conversions of Example 3 to Examples 27, Example 8 to Example 28 and 29, Example 21 to Example 32 and 33, Example 4 to Examples 41, Example 9 to Example 43, and Example 66 to Example 75), amine exchange at the 2-position of the 5-(pyridin-3-yl) substituent (see conversions of Example 7 to Examples 78), reactions at a nitrogen containing substituent, such as reductive alkylation (Example 18 to Example 21), acetamide formation (Examples 18, and 20 to Examples 22 and 24 respectively) or sulphonamide formation (Preparations 68, 67 to Examples 25 to 62 respectively), and reduction of a nitro functionality to provide an amino group (Example 63 to Example 64). The deprotection and transformations described herein and as illustrated in the Examples and Preparations sections may be effected in a xe2x80x9cone-potxe2x80x9d procedure (see for example the conversion of the compound of preparation 65 into the compound of example 26).
The following processes are illustrative of the general synthetic procedures which may be adopted in order to obtain the compounds of the invention.
1. A compound of formula (I): 
wherein formula (I) may equally be represented by general formulae (IA) and (IB) and wherein R1, R2, R4 and R13 are as previously defined herein may be prepared from a compound of general formula (IX): 
wherein Rp is R13 (i.e. OR3 or NR5R6) or X wherein R13, R R5 and R6 are as defined hereinbefore and X is a leaving group and wherein general formula (IX) can be represented by formulae (IXA), (IXB) or (IXC) respectively: 
wherein R1, R2, R3, R4, R5 and R6 are as previously defined herein and wherein X is a leaving group and may be any group which is displaceable by an amino group of the formula xe2x80x94NR5R6 or by an alkoxy group and wherein the intermediate compounds of general formulae (IXA) and (IXB) can be represented by their regioisomeric general formulae as previously illustrated for compounds having the general formulae (I). Suitable leaving groups, X, for use herein include halogen, alkoxy, amino, tosylate groups and further groups are detailed hereinafter.
1.1 A compound of formula (I) wherein R13xe2x95x90NR5R6 may be prepared by cyclisation of a compound of general formula (IXA): 
wherein R1, R2, R4, R5 and R6 are as previously defined herein for compounds of the formula (I), (IA) or (IB). Preferably, the cyclisation is base-mediated, using an alkali metal salt of a sterically hindered alcohol or amine. For example, the required cyclisation may be effected using about a 1- to 5-, preferably a 1.2- to 3.5-fold excess of potassium t-butoxide, potassium bis(trimethylsilyl)amide or cesium carbonate, optionally in the presence of molecular sieves, in a suitable solvent, such as for example an inert solvent e.g. DMF or NHR5R6 or mixtures thereof, at the reflux temperature of the reaction mixture optionally in the presence of about a 1 molar equivalent of ethyl acetate or ethyl pivalate, or, the reaction can optionally be carried out in a sealed vessel at about 100-130xc2x0 C. optionally in the presence of about a 1 molar equivalent of ethyl acetate or ethyl pivalate.
1.2 A general route for the synthesis of compounds (I) via compounds (IXB) is illustrated in Scheme 1 wherein said intermediate compounds (IXB) have the general formula: 
wherein R1, R2 and R4 are as previously defined herein for compounds of the formula (I), (IA) and (IB) and wherein X is a leaving group as defined hereinbefore, by reaction in the presence of xe2x80x94OR3 and a hydroxide trapping agent. The conversion (IXB) to (I) can be undertaken in either a stepwise process or a one-pot process. A number of stepwise permutations are feasible, some of which are subsets of others. These include
i) cyclisation (IXB to XXX) followed by displacement (XXX to I);
ii) cyclisation (IXCa to XXX) followed by displacement (XXX to I);
iii) displacement (IXB to IXC) followed by cyclisation (IXC to I); and
iv) displacement (IXCa to IXC) followed by cyclisation (IXC to I) wherein compounds (XXX) and (IXCa) have the general formulae: 
wherein R1, R2, R4 and X are as defined herein before and OR3a is an alkoxy group which is different from and displaceable by the desired OR3 group on the final compounds of general formula (I) and wherein R3ais selected from C1 to C6 alkyl optionally substituted with one or two substituents selected from C3 to C5 cycloalkyl, hydroxy, C1 to C4 alkoxy, benzyloxy, NR5R6, phenyl, Het1, Het2, Het3 or Het4 wherein the C1 to C6 alkyl and C1 to C4 alkoxy groups may optionally be terminated by a haloalkyl group such as CF3 and wherein the C3-C5 cycloalkyl group may optionally be substituted by C1-C4 alkyl, hydroxy or halo; C3 to C6 cycloalkyl; Het1, Het2, Het3 or Het4. Preferably R3a is C1 to C6 alkyl.
To effect initial displacement without significant simultaneous cyclisation it is preferred that the displacement with xe2x80x94OR3 (in (iii) or (iv)) is carried out in the range of from about 80xc2x0 C. to about 90xc2x0 C. to provide a compound of the general formula (IXC). Subsequent cyclisation to a compound of general formula (I) is generally carried out at a temperature greater than about 115xc2x0 C. To effect initial cyclisation without significant simultaneous displacement it is preferred that, for (IXCa) to (XXX) (in (ii)), the reaction is conducted at a temperature greater than about 110xc2x0 C. with xe2x80x94OR3a in R3aOH Subsequent displacement to a compound of general formula (I) is generally carried out with xe2x80x94OR3 in R3OH in the range of from about 80xc2x0 C. to about 90xc2x0 C.
For conversion of (IXB) to (I) (ie. (i) above), it may be preferred to obtain compounds of general formula (I) directly from compounds of general formula (IXB) since both the cyclisation and displacement components of this reaction can be carried out in a xe2x80x9cone-potxe2x80x9d reaction. Such a xe2x80x9cone-potxe2x80x9d process can be run at lower pressures (ie. nearer ambient pressure) than say a stepwise cyclisation and displacement process (ie. (ii) above) if the boiling point of R3OH is higher than that of R3a OH and where the ambient boiling point of R3aOH is less than about 115xc2x0 C. (ie. too low to effect cyclisation at ambient pressure). It should be noted that is may still be necessary to operate such processes at higher temperatures than the boiling point of HOR3, i.e. at higher pressure.
In the case of compounds of general formula (IXC) as detailed hereinafter wherein X is OR3, compounds of general formula (I) can be obtained by direct cyclisation by reacting in the presence of an auxiliary base, a hydroxide trapping agent and an appropriate solvent R3OH or an inert solvent or a combination thereof.
The temperature of the reaction of compounds of the general formula (IXB) to compounds of the general formula (I) (such as the corresponding formation of compounds (IA) and (IB)) is preferably at least about 80xc2x0 C. more preferably about 80 to about 130xc2x0 C. more preferably still about 100 to about 130xc2x0 C. and most preferably about 115 to about 125xc2x0 C. These temperatures are also applicable for the conversion of compounds (XXX) to (I), although the temperature in this case could also probably be lower (e.g. about 600xc2x0 C.) since there is no cyclisation taking place.
Preferably compounds of formula (I), or (IA), or (IB) wherein
R1 is xe2x80x94(CH2)n(C3-C4)cycloalkyl wherein n is 1 or 2; or
R1 is xe2x80x94(CH2)n(C3-C6)cycloalkyl wherein n is 0; or
R1 is -cyclopentylmethyl; or
R1 is methyl, ethyl, i-propyl or n-propyl substituted by methoxy, ethoxy, n-propoxy or i-propoxy wherein said alkoxy substituent may be directly attached to any C-atom within the ethyl, iso-propyl or n-propyl groups other than the C-atom directly linked to the pyrazole ring; or
R1 is i-, n-, sec- or t-butyl;
R2 is C2 to C4 alkyl; R13 is OR3 wherein the R3 alkyl group is methyl, ethyl, n-propyl, i-propyl, i- butyl, n- butyl, sec-butyl or t-butyl optionally substituted with one or two methoxy, ethoxy, n-propoxy or i-propoxy substituents; and R4 is a 4-methyl, 4-ethyl, 4-n-propyl or 4-i-propylpiperazin-1-ylsulphonyl group are prepared from compounds of general formula (IXB) wherein X is OR3 (i.e. compounds of general formula (IXC) as detailed hereinbefore and after).
Thus, according to a further aspect of the present invention there is provided a further process for the preparation of a compound of general formula (I): 
or a compound of general formula (IA), or (IB) wherein
R1 is xe2x80x94(CH2)n(C3-C4)cycloalkyl wherein n is 1 or 2; or
R1 is xe2x80x94(CH2)n(C3-C6)cycloalkyl wherein n is 0; or
R1 is -cyclopentylmethyl; or
R1 is methyl, ethyl, i-propyl or n-propyl substituted by methoxy, ethoxy, n-propoxy or i-propoxy wherein said alkoxy substituent may be directly attached to any C-atom within the ethyl, iso-propyl or n-propyl groups other than the C-atom directly linked to the pyrazole ring; or
R1 is i-, n-, sec- or t-butyl;
R2 is C2 to C4 alkyl; R13 is OR3 wherein the R3 alkyl group is methyl, ethyl, n-propyl, i-propyl, i- butyl, n- butyl, sec-butyl or t-butyl optionally substituted with one or two methoxy, ethoxy, n-propoxy or i-propoxy substituents; and R4 is a 4-methyl, 4-ethyl, 4-n-propyl or 4-i-propylpiperazin-1-ylsulphonyl group comprising reacting a compounds of general formula (IXC): 
wherein R1, R2, R3 and R4 are as defined previously herein, wherein said reaction is carried out in the presence of xe2x80x94OR3 and a hydroxide trapping agent, or alternatively reacting in the presence of hydroxide trapping agent and an auxiliary base.
Intermediates of the general formula (IXC) and more specifically (IXCA) and (IXCB) form further aspects of the invention. 
A particular advantage of the use of the hydroxide trapping agent is that a higher yield of final product (compounds of general formula (I), (IA) or (IB)) can be obtained than for the same reaction where the trapping agent is not present.
Preferably the hydroxide trapping agent is an ester. More preferably said hydroxide trapping agent is an ester of the formula: 
wherein OT is OR3 or the residue of a bulky alcohol or a non-nucleophilic alcohol or TOH is an alcohol which can be azeotropically removed during the reaction; and C(O)V is the residue of a carboxylic acid. For example, where OR3 is OEt in compound (IXC) the hydroxide trapping agent (TOC(O)V) could be e.g. ethyl acetate or ethyl pivalate. Preferably V is a C1 to C4 alkyl group.
Preferably X is selected from the group consisting of xe2x80x94OR3, halo, optionally substituted arylsulphonyloxy, preferably phenylsulphonyloxy, more preferably a para-substituted aryl (phenyl) such as by a C1-C4 alkyl group e.g. p-toluenesulphonyloxy; C1-C4 alkylsulphonyloxy e.g. methanesulphonyloxy; nitro or halo substituted benzenesulphonyloxy preferably para-substituted e.g. p-bromobenzenesulfonyloxy or p-nitrobenzenesulphonyloxy; C1-C4 perfluoroalkylsulphonyloxy e.g. trifluoromethylsulphonyloxy; optionally substituted aroyloxy such as benzoyloxy; C1-C4 perfluoroalkanoyloxy such as trifluoroacetyloxy; C1-C4 alkanoyloxy such as acetyloxy; diazonium; quatenaryammonium C1-C4 alkylsulphonyloxy; halosulphonyloxy e.g. fluorosulphonyloxy and other fluorinated leaving groups; and diarylsulphonylamino e.g. ditosyl (NTs2).
More preferably, X is a C1-C6 primary or secondary alkoxy and is especially a C1-C4 alkoxy group such as ethoxy or methoxy.
xe2x80x94OR3 can act both as a nucleophile (to displace the leaving group by nucleophilic substitution) and as a base (to bring about the cyclisation).
xe2x80x94OR3 can be generated in solution from, for example, a salt ZOR3 (wherein Z is a cation) such as a metal salt. More particularly an alkali (such as sodium or potassium) or alkaline earth metal salt of xe2x80x94OR3 in a suitable solvent would give rise to xe2x80x94OR3 in solution. In another embodiment, xe2x80x94OR3 is formed in situ from R3OH plus an auxiliary base (i.e. a base other than xe2x80x94OR3). However, in another system, ZOR3 could be used in the reaction system with an auxiliary base.
As will be appreciated the solvent in which the reaction takes place can be R3OH or an inert solvent (or a mixture of both). By inert solvent we mean a solvent which will not form a nucleophile under the reaction conditions or if a nucleophile is formed it is sufficiently hindered or unreactive such that it does not substantially compete in the displacement reaction. When R3OH is used as a source of xe2x80x94OR3, then a separate solvent is not essentially required but an (auxiliary) inert solvent (i.e. a solvent other than R3OH) may be used as a co-solvent in the reaction.
Suitable solvents are as follows: R3OH, a secondary or tertiary C4-C12 alkanol, a C3-C12 cycloalkanol, a tertiary C4-C12 cycloalkanol, a secondary or tertiary (C3-C7 cycloalkyl)C2-C6 alkanol, a C3-C9 alkanone, 1,2-dimethoxyethane, 1,2-diethoxyethane, diglyme, tetrahydrofuran, 1,4-dioxan, toluene, xylene, chlorobenzene, 1,2-dichlorobenzene, acetonitrile, dimethyl sulphoxide, sulpholane, dimethylformamide, N-methylpyrrolidin-2-one, pyridine, and mixtures thereof.
More preferably, the solvent is R3OH, a tertiary C4-C12 alkanol, a tertiary C4-C12 cycloalkanol, a tertiary (C3-C7 cycloalkyl)C2-C6 alkanol, a C3-C9 halkanone,1,2-dimethoxyethane, 1,2-diethoxyethane, diglyme, tetrahydrofuran, 1,4-dioxan, toluene, xylene, chlorobenzene, 1,2-dichlorobenzene, acetonitrile, dimethyl sulphoxide, sulpholane, dimethylformamide, N-methylpyrrolidin-2-one, pyridine, and mixtures thereof.
Most preferably the solvent is R3OH, which means that xe2x80x94OR3 is formed in situ, such as in the presence of an auxiliary base.
A wide range of auxiliary bases can be used in the process of the invention. Typically the bases would not substantially compete with xe2x80x94OR3 in the nucleophilic substitution of X (i.e. they would be non nucleophilic) such as by suitably being sterically hindered.
Preferably the auxiliary base is selected from the group consisting of a sterically hindered base, a metal hydride, metal oxide, metal carbonate and metal bicarbonate.
The sterically hindered base is advantageously a metal salt of a sterically hindered alcohol or amine.
More preferably the auxiliary bases in accordance with the invention are selected from the group consisting of metal salts of a sterically hindered alcohol or amine such as a secondary or tertiary C4-C12 alkanol, a C3-C12 cycloalkanol and a secondary or tertiary (C3-C8 cycloalkyl)C1-C6 alkanol, a N-(secondary or tertiary C3-C6 alkyl)-N-(primary, secondary or tertiary C3-C6 alkyl)amine, a N-(C3-C8 cycloalkyl)-N-(primary, secondary or tertiary C3-C6 alkyl)amine, a di(C3-C8 cycloalkyl)amine or hexamethyldisilazane; 1,5-diazabicyclo[4,3,0]non-5-ene and 1,8-diazabicyclo[5,4,0]undec-7-ene; a metal hydride, oxide, carbonate, and bicarbonate.
Yet more preferably the auxiliary bases in accordance with the invention are selected from the group consisting of metal salts of a sterically hindered alcohol or amine such as a tertiary C4-C12 alkanol, a C3-C12 cycloalkanol and a tertiary (C3-C8 cycloalkyl)C1-C6 alkanol, a N-(secondary or tertiary C3-C6 alkyl)-N-(primary, secondary or tertiary C3-C6 alkyl)amine, a N-(C3-C8 cycloalkyl)-N-(primary, secondary or tertiary C3-C6 alkyl)amine, a di(C3-C8 cycloalkyl)amine or hexamethyidisilazane; 1,5-diazabicyclo[4,3,0]non-5-ene and 1,8-diazabicyclo[5,4,0]undec-7-ene; a metal hydride, oxide, carbonate, and bicarbonate.
More preferably still, the auxiliary base is selected from the sterically hindered bases of the previous paragraph (i.e. all of them except the metal hydride, oxide, carbonate and bicarbonate).
Most preferably still, the auxiliary base is the metal salt of a tertiary C4-C6 alcohol such as the alkali or alkaline earth metal salts (e.g. Na/K) of t-butanol or t-amyl alcohol, or the base is KHMDS.
Most preferably, the auxiliary base is the alkali metal salt of t-butanol (e.g. potassium t-butoxide).
The metal of the salt of ZOR3 and the auxiliary base can be independently selected from alkali metals (lithium, sodium, potassium, rubidium, cesium) or alkaline earth metals (beryllium, magnesium, calcium, strontium, barium).
Preferably the metal is sodium, potassium, lithium or magnesium. More preferably the metal is sodium or potassium.
To maximize yields, it is further preferred that when X is any group hereinbefore defined except xe2x80x94OR3, then at least about 1 molecular equivalent of auxiliary base and xe2x80x94OR3 are used. If xe2x80x94OR3 also functions as a base (i.e. there is no auxiliary base present) then preferably at least about 2 equivalents of xe2x80x94OR3 are present. Suitably, at least about 1 equivalent of trapping agent (preferably at least about 2 equivalents) is present. In the case where X=OR3 (i.e. starting from (IXC) rather than (IXB) then, in theory, at least 1 equivalent of base is required, wherein said base may be xe2x80x94OR3 or auxiliary base.
The temperature of the reaction of compounds of the general formula (IXC) to compounds of the general formula (I) (such as the corresponding formation of compounds (IA) and (IB)) is preferably at least about 80xc2x0 C. more preferably about 80 to about 130xc2x0 C. more preferably still about 100 to about 130xc2x0 C. and most preferably about 115 to about 125xc2x0 C.
The reaction temperature attainable to effect the conversion of compounds of the general formulae (IXB), (IXC) or (XXX) to compounds of the general formula (I) depends on the solvent, the nature of xe2x80x94OR3 and X. When X is OR3a (wherein OR3a and OR3 are not the same), i.e. a compound of the formula (IXCa) and R3OH is the solvent, preferably XH (such as C1-C6 alcohol) is removed azeotropically (of course the reaction vessel must be configured to distill over the azeotrope mixture) with R3OH by running the reaction at the azeotrope temperature of XH and R3OH. In this way the yield and quality of the final product can be further improved. For example, (where X is an alkoxy, preferably ethanol) the conversion of compound (XXX), (IXB) or (IXC) to (I) is preferably carried out at the azeotrope temperature of the alcohol (i.e. XH (preferably ethanol)) with R3OH. When X=OR3 and the solvent is R3OH there is no requirement to azeotrope out R3OH.
Thus in a preferred embodiment of the present invention there is provided a process for the synthesis of compounds of general formula (I), (IA) or (IB) and in particular compounds of general formula (I), (IA) or (IB) wherein R1 is xe2x80x94(CH2)n(C3-C4)cycloalkyl wherein n is 1 or 2; or R1 is xe2x80x94(CH2)n(C3-C6)cycloalkyl wherein n is 0; or R1 is xe2x80x94(CH2)n(C5)cycloalkyl wherein n is 1; or R1 is methyl, ethyl, i-propyl or n-propyl substituted by methoxy, ethoxy, n-propoxy or i-propoxy wherein said alkoxy substituent may be directly attached to any C-atom within the ethyl, iso-propyl or n-propyl groups; or R1 is i-, n-, sec- or t-butyl; R2 is C2 to C4 alkyl; R13 is OR3 wherein the R3 alkyl group is methyl, ethyl, n-propyl, i-propyl, i- butyl, n- butyl, sec-butyl or t-butyl optionally substituted with one or two methoxy, ethoxy, n-propoxy or i-propoxy substituents; and R4 is a 4-methyl, 4-ethyl, 4-n-propyl or 4-i-propylpiperazin-1-ylsulphonyl group wherein said process comprises reacting a compound of general formula (XIB), (XIC) or (XID) respectively:
a) with R3OH and auxiliary base, optionally in an inert solvent and in the presence of said trapping agent; or
b)with ZOR3 and an auxiliary base in R3OH or an inert solvent or both, in the presence of said trapping agent; or
c)with ZOR3 and R3OH or an inert solvent or both, in the presence of said trapping agent; or
d) with auxiliary base, inert solvent or R3OH or a combination thereof and a hydroxide trapping agent for compounds of the general formula (IXC).
1.3 For compounds of the general formula (IXB) wherein X is OR3 and an alcohol is selected as solvent a compound of formula (I) may be prepared by cyclisation of a compound of general formula (IXC): 
wherein R1, R2, R3 and R4 are as previously defined herein for compounds of the formula (I), (IA) and (IB). In said reaction the appropriate alcohol of formula R3OH should be employed as the solvent in order to obviate potential problems associated with alkoxide exchange at the 2-position of the pyridine ring or an inert solvent or a mixture of the two. The appropriate alcohol as defined herein means that the solvent alcohol should be of the same alkyl chain length as the alkoxy (xe2x80x94OR3) substituent, for example, where xe2x80x94OR3 is ethoxy, ethanol is the appropriate alcohol. Preferably, said cyclisation is base-mediated, using an alkali metal salt of a sterically hindered alcohol or amine. For example, the required cyclisation may be effected using about a 1- to 8, preferably about a 1- to 5-, more preferably a 1.2- to 3.5-fold excess of potassium t-butoxide or potassium bis(trimethylsilyl)amide, optionally under suitable drying conditions i.e. in the presence of molecular sieves or under azeotroping conditions, in a suitable solvent as described above at the reflux temperature of the reaction mixture optionally in the presence of about 1 to 2 molar equivalents of a hydroxide trapping agent such as ethyl acetate or ethyl pivalate, or, the reaction can optionally be carried out in a sealed vessel at about 100-300xc2x0 C. optionally in the presence of about 1 to 2 molar equivalents of a hydroxide trapping agent such as ethyl acetate or ethyl pivalate.
Alternative reaction conditions for the cyclisation reactions of compounds of (IXC) wherein X is OR3 are to conduct the reaction with about 1.2 to 4.5 molecular equivalents of sterically hindered base such as potassium t-butoxide or KHMDS, optionally in a sealed vessel at from about 100xc2x0 C. to about 150xc2x0 C. with, rather than an alcohol of formula R3OH as solvent, a sterically hindered alcohol, e.g. 3-methylpentan-3-ol, as solvent optionally in the presence of about 1 or 2 molar equivalents of ethyl acetate or ethyl pivalate.
A compound of formula (IXA) or a compound of general (IXB) wherein X is OR3 (i.e. a compound of general formula (IXC)) may be prepared by a coupling reaction between a compound of formula (VII): 
wherein R1 and R are as previously defined for formulae (IXA), (IXB) or (IXC) with a compound of formula (XA), (XB) or (XC) respectively: 
wherein R3, R4, R5, R6 and X are also as previously defined for formulae (IXA), (IXB) or (IXC). Where either R5 and/or R6 in the xe2x80x94NR5R6 group of formula (XA) are H, then a suitable N-protecting group strategy may be advantageously employed. Any known suitable protecting group strategy may be used.
The coupling reaction may be carried out using conventional amide bond-forming techniques, e.g. via the acyl chloride derivative of (XA) or (XB) in the presence of up to about a five-fold excess of a tertiary amine such as triethylamine or pyridine to act as scavenger for the acid by-product (HY), optionally in the presence of a catalyst such as 4-dimethylaminopyridine, in a suitable solvent such as dichloromethane, at from about 0xc2x0 C. to about room temperature. For convenience pyridine may also be used as the solvent.
In particular, any one of a host of amino acid coupling variations may be used. For example, the acid of formula (XA), (XB) or (XC) or a suitable salt (e.g. sodium salt) thereof may be activated using a carbodiimide such as 1,3-dicyclohexylcarbodiimide or 1-ethyl-3-(3-dimethylaminoprop-1-yl)carbodiimide optionally in the presence of 1-hydroxybenzotriazole hydrate and/or a catalyst such as 4-dimethylaminopyridine, or by using a halotrisaminophosphonium salt such as bromotris(pyrrolidino)phosphonium hexafluorophosphate or by using a suitable pyridinium salt such as 2-chloro-1-methylpyridinium iodide. Either type of coupling is conducted in a suitable solvent such as dichloromethane, tetrahydrofuran or N,N-dimethylformamide, optionally in the presence of a tertiary amine such as triethylamine or N-ethyldiisopropylamine (for example when either the compound of formula (VII), or the activating reagent, is presented in the form of an acid addition salt), at from about 0xc2x0 C. to about room temperature. Preferably, from 1 to 2 molecular equivalents of the activating reagent and from 1 to 3 molecular equivalents of any tertiary amine present are employed.
In a further variation, the carboxylic acid function of (XA), (XB) or (XC) may first of all be activated using up to about a 5% excess of a reagent such as N,N-carbonyidiimidazole in a suitable solvent, e.g. ethyl acetate or butan-2-one, at from about room temperature to about 80xc2x0 C. followed by reaction of the intermediate imidazolide with (VII) at from about 20xc2x0 C. to about 90xc2x0 C.
It will be appreciated that the general formula (VII) can also be represented by the regioisomeric formulae (VIIA) and (VIIB): 
wherein R1 and R2 are as previously defined herein.
The 4-aminopyrazole-5-carboxamide compounds having the general formulae (VII), (VIIA) or (VIIB) may be prepared from pyrazole compounds of the general formula (XIII): 
wherein Rq is selected from OH, C1-C6 alkoxy or NR5R6 wherein R5 and R6 are as hereinbefore defined, according to the procedures detailed in the preparations section herein and as particularly described in Preparations 96(a) to (h).
Compounds having the general formulae (XA) or (XC) may be prepared from the carboxylic acid compounds of the general formulae (VIIIA), (VIIIB) or (VIIIC) respectively: 
wherein R3, R5 and R6 are as defined for compounds of the general formulae (I), (IA) and (IB) by reaction with a 4-R1l-piperizinyl compound, such as for example 4-methylpiperizine. Such reaction can be conducted at from about 0xc2x0 C. to about room temperature, preferably in the presence of an appropriate solvent such as a C1 to C3 alkanol or dichloromethane optionally in the presence of a suitable base such as triethylamine to scavenge the acid by-product (HY). Where either R5 or R6 is H a suitable amino protecting group strategy may be employed as detailed hereinbefore.
Compounds of the general formulae (VIIIA), (VIIIB) or (VIIIC) may be prepared from compounds of the general formulae (XIA), (XIB) or (XIC) respectively: 
wherein R3, R5, R6 and X are as defined for compounds of the general formulae (I), (IA) and (IB) by the application of known methods for converting amino to an SO2Y group, wherein Y is halo, preferably chloro. For example, when Y is chloro, by the action of about a two-fold excess of sodium nitrite in a mixture of concentrated hydrochloric acid and glacial acetic acid at from about xe2x88x9225xc2x0 C. to about 0xc2x0 C. followed by treatment with excess liquid sulphur dioxide and a solution of about a three-fold excess of cupric chloride in aqueous acetic acid at from about xe2x88x9215xc2x0 C. to about room temperature. When R13 contains a primary or secondary amino group, protection of the said amino group with an acid stable group such as acetyl or benzyl will generally be advantageous.
Compounds of the general formula (XIA), (XIB) and (XIC) may be prepared by reduction of compounds of the general formulae (XIIA), (XIIB) and (XIIC) respectively: 
wherein R3, R5, R6 and X are as previously defined. Such conversion of compounds of the general formulae (XIIA), (XIIB) and (XIIC) to compounds of the general formulae (XIA), (XIB) and (XIC) can be achieved by conventional catalytic or catalytic transfer hydrogenation procedures. Typically, the hydrogenation is achieved using a Raney (RTM) nickel catalyst or a palladium catalyst such as 10% Pd on charcoal, in a suitable solvent such as ethanol at a hydrogen pressure of from about 345 kPa (50 psi) to about 414 kPa (60 psi) at from about room temperature to about 60xc2x0 C. preferably from about 40xc2x0 C. to about 50xc2x0 C.
Intermediates of the general formula (IXC) as described in 1.2 and 1.3 hereinbefore can be prepared via a coupling reaction between a compound of the general formula (XB) and a compound of the general formula (VII) wherein said coupling may be achieved by any of the methods described hereinbefore. Compounds of general formula (XB) may be prepared according to the route outlined in Scheme 2.
With reference to Scheme 2, the intermediate of formula (XB) is formed from a compound of formula (XIV), the exact process being dependent on leaving group X.
For compounds of formula (XB) wherein X=arylsulfonyloxy, C1-C4 alkylsulfonyloxy, C1-C4 perfluoroalkylsulfonyloxy, aryloxy, C1-C4 perfluoroalkanoyloxy, C1-C4 alkanoyloxy, quarternaryammonium C1-C4 alkylsulfonyloxy or halosulfonyloxy, compound (XB) can be formed from compounds (XIV) (wherein Q=OH and W=OH) and an appropriate derivatising agent, more particularly an appropriate sulphonylating agent such as arylsulfonylhalide, C1-C4 alkylsulfonylhalide, C1-C4 perfluoroalkylsulfonylhalide, arylhalide, C1-C4 perfluoroalkanoylhalide, C1-C4 alkanoylhalide, quarternary ammonium C1-C4 alkylsulfonylhalide or halosulfonylhalide, or an appropriate arylating agent such as arylhalide, or an appropriate acylating agent such as C1-C4 perfluoroalkanoylhalide, or C1-C4 alkanoylhalide), respectively (preferably the halide substituent of the above is chloride), in an appropriate solvent. Compounds of formula (XIV) (wherein Q=OH and W=OH) can be formed from compounds (XV) (wherein P is hydrolyzable group) via use of a hydrolysis agent, preferably a hydroxide base (ideally 2 molar equivalents), more preferably a metal hydroxide such as sodium hydroxide, in an appropriate solvent, such as water. The metal of the hydroxide base can be as defined hereinbefore for Z (in ZOR). This will also apply for other reactions of scheme 2 and 3 hereafter where hydroxide base/hydrolysis agent is used. Where P is group which is not hydrolyzable by hydroxide then a suitable de-protection strategy should be employed according to standard literature practice.
Compounds of formula (XB) where X=chloro, can be formed from (XIV) wherein Q=Cl and W=P (such as OEt) (i.e. formula XV) and a hydroxide base (ideally 1 molar equivalent), such as sodium hydroxide preferably in an appropriate solvent, such as water and a deprotecting agent.
Preferably the deprotecting agent as used herein in accordance with the invention is a hydrolysing agent, more preferably a hydroxide nucleophile, advantageoulsly a hydroxide base (ideally 1 molar equivalent), such as sodium hydroxide preferably in an appropriate solvent, such as water.
Compounds of formula (XB) wherein X=diazonium, can be formed from (XIV) (wherein Q=NH2, W=OH) and nitrous acid. Compounds of formula (XIV) (wherein Q=NH2, W=OH) can be formed from compounds of formula (XIV) (wherein Q=NH2, W=P, e.g. OEt) and a deprotecting agent such as a hydroxide base e.g. sodium hydroxide, in an appropriate solvent, such as water. Intermediate (XIV) (Q=NH2, W=P, e.g. OEt) is formed from (XV) and an ammoniating agent, such as ammonia, in an appropriate solvent, such as water.
Compounds of formula (XB) wherein X=diarylsulfonylamino, can be formed from (XIV) (wherein Q=NH2, W=OH) and an appropriate derivatising agent, preferably an appropriate sulphonylating agent such as arylsulphonylhalide, preferably arysulfonylchloride (ideally at least 2 molar equivalents) and preferably in the presence of a base (ideally 2 molar equivalents thereof), such as triethylamine in an appropriate solvent.
Compounds of formula (XB) wherein X=C1-C6 (preferably C1-C4) preferably primary or secondary alkoxy, can be formed from (XIV) (wherein Q=C1-C6 (preferably C1-C4) primary or secondary alkoxy and W=P, such as OEt) and a deprotecting agent (for P=OEt), preferably a hydroxide base, such as sodium hydroxide, in an appropriate solvent, such as water. Compounds of formula (XIV) (wherein Q=C1-C6 (preferably C1-C4) primary or secondary alkoxy, W=P e.g. OEt) can be formed from (XV) and an appropriate alkoxide, ORxe2x88x92 wherein R is C1-C6 alkyl more preferably C1-C4 primary or secondary alkyl, such as sodium ethoxide in an appropriate solvent such as toluene. Most preferably P=X (wherein X is an alkoxy) since this avoids trans-esterification issues.
The compounds of formula (XV) can be formed from compounds of formula (XVI) by reaction with a mono-N-substituted piperazine group wherein the mono-substituent R10 as defined herein before, optionally in the presence of a supplementary base (which does not react irreversibly with the sulphonyl chloride moiety) such as triethylamine preferably in an appropriate solvent, such as toluene. xe2x80x9cDxe2x80x9d in compounds (XV) and (XVI) is Cl or Br. The monosubstituted piperazine group may also be the base where more than one equivalent of monosubstituted piperazine is present. Preferably about 2 equivalents are used.
Where a supplementary base is used it either does not react with the sulphonyl chloride moiety (such as a metal oxide, carbonate or bicarbonate) or it reacts with the sulphonyl chloride moiety in such a way as to keep it activated to nucleophilic attack (e.g. a tertiary amine such as triethylamine). The amine NH(R3)(R4) may also act as a base, in which case preferably more than one equivalent is present, more preferably about 2 equivalents (or more).
The compounds of formula (XVI) can be formed from compounds of formula (XX) in the presence of a chlorinating or brominating agent such as thionyl chloride or thionyl bromide more preferably in the presence of a halogenation catalyst, more preferably still thionyl chloride or thionyl bromide in the presence of dimethylformamide. The thionyl chloro/bromo can also act as the solvent, but more preferably the reaction takes place or in an appropriate other solvent such as toluene. In such case only stoicheometric amounts of thionyl chloride/bromide would be required, preferably at least 2 molar equivalents, more preferably at least 5 molar equivalents.
It is possible to undertake the four step conversion of (XX) to (XB) in a single telescoped step, without intermediate product isolation, using the same solvent throughout (hereinafter the xe2x80x9ctelescoping solventxe2x80x9d). Thus where X is an alkoxy group (xe2x80x94OR3 group), steps (XX) to (XB) can be telescoped together using a single solvent such as a water immiscible inert organic solvent. More preferably a hydrocarbon solvent (such as toluene, xylene, anisole, chlorobenzene, hexane, heptane, octane, nonane, decane, cyclohexane, methylcyclohexane) or ethers (such as dibutyl ether, diphenyl ether) or ketones (such as methylisobutylketone, methylethylketone) or esters (such as ethyl acetate, butyl acetate) or dimethylformamide. More preferably still a hydrocarbon solvent (such as toluene, xylene, anisole, chlorobenzene, octane, nonane, decane, methylcyclohexane) or ethers (such as dibutyl ether, diphenyl ether) or esters (such as ethyl acetate, butyl acetate). More preferably still the telescoping solvent is toluene.
The intermediate of formula (XX) is formed from a compound of formula (XVII) in the presence of an agent which will form a protecting group (P) for the carboxylic acid (i.e. to form the xe2x80x94COP group). Preferably said agent is an esterification agent, to form a carboxylic acid ester (wherein, e.g. P will be alkoxy and the protecting forming agent will be an alcohol) such as a C1-C6 carboxylic acid ester which will be carried through the reaction scheme and hydrolized under basic conditions to the carboxylic acid function of compound (XB). Most preferably the esterification agent is ethanol. An additional solvent such as toluene may be appropriate.
The intermediate of formula (XVII) is formed from 2-hydroxynicotinic acid or a salt thereof in the presence of a sulphonylating agent, more preferably an agent comprising SO3 (ideally at least 1 molar equivalent of SO3), for example using SO3 in an organic solvent (e.g. THF, dioxan and heptane) or an aprotic solvent (e.g. nitrobenzene, nitromethane, 1,4-dioxane, dichloromethane) or a mineral acid as solvent (e.g. sulphuric acid) or in a liquid carboxylic acid as solvent (e.g. acetic acid) or THF or heptane. More preferably still, the sulphonylating agent is oleum (SO3 in sulphuric acid) such as about 20% to 30% oleum.
Compounds of the general formula (IXB) are formed by the reaction of intermediates of general formula (XB) with compounds of the general formula (VII), as detailed hereinbefore in the presence of a coupling agent, such as N,Nxe2x80x2-carbonyldiimidazole and a suitable solvent, such as ethyl acetate.
Methods for the preparation of compounds of the general formula (VII) are described hereinafter.
In a preferred embodiment of Scheme 2, X is an xe2x80x94OR3 alkoxy group and so Q in compound (XIV) represents OR3. Preferably OR3 is a C1 to C6 alkoxy group, more preferably a C1 to C4 primary or secondary alkoxy group and especially ethoxy. However for other leaving groups the general method for Scheme 2 would apply.
This preferred embodiment of Scheme 2 is illustrated in Scheme 3. In Scheme 3 the intermediate of formula (XB) is formed from a compound of formula (XIV) by removal of protecting group P by a deprotecting agent, advantageously by saponification in the presence of a hydroxide base such as sodium hydroxide, preferably in an appropriate solvent such as water and toluene.
The intermediate of formula (XIV) is formed from a compound of formula (XV) in the presence of an appropriate C1-C6 alkoxide nucleophile (xe2x80x94OR3), (such as a primary or secondary alkoxide), preferably a metal alkoxide of the formula ZOR3, wherein the metal (Z) is as defined hereinbefore for ZOR, such as sodium ethoxide, preferably in an appropriate solvent such as toluene or R3OH, wherein R3OH is as defined hereinbefore and is preferably ethoxy. D in compounds of formulae (XV) and (XVI) is Cl or Br, more preferably D is Cl.
The intermediate of formula (XV) is formed from a compound of formula (XVI) by reaction with Nxe2x80x94R10piperazine, preferably in the presence of a base, such as triethylamine or excess Nxe2x80x94R10piperazine, preferably in an appropriate solvent such as toluene.
The intermediate of formula (XVI) is formed from a compound of formula (XX) in the presence of a chlorinating or brominating agent as defined for the same step in Scheme 2 such as thionyl chloride or bromide, preferably thionyl chloride or bromide/dimethylformamide. The former can also act as the solvent, but more preferably the reaction takes place in an appropriate other solvent, such as toluene. In such a case only stoicheiometric amounts of thionyl chloride/bromide would be required, preferably as at least 2 molar equivalents more preferably at least 5 molar equivalents.
The intermediate of formula (XX) is formed from a compound of formula (XVII) in the presence of an agent which will form a protecting group (P) for the carboxylic acid (i.e. to form the xe2x80x94COP group) as defined herein before. Preferably said agent is an esterification agent, to form a carboxylic acid ester such as a C1-C6 carboxylic acid ester which will be carried through the reaction scheme and hydrolysed under basic conditions to the carboxylic acid function of compound (XB). Most preferably the esterification agent is ethanol. An additional solvent such as toluene may be utilised as appropriate.
The intermediate of formula (XVII) is formed from 2-hydroxynicotinic acid with a sulphonylating agent such as 30% oleum.
Again it is possible to undertake the four step conversion of (XX) to (XB) in a single telescoped step (as set out hereinbefore) in the same pot, without intermediate product isolation, using the same solvent (herein the xe2x80x9ctelescopingxe2x80x9d solvent) throughout. The list of solvents described with respect to Scheme 2 are directly applicable here. Most preferably the solvent is toluene.
For example after formation of compound (XVI), the excess chlorinating/brominating agent could be azeotroped off at the azeotrope temperature of the said agent and the telescope solvent. After formation of compound (XV), the HBr/HCl (i.e. HD) salts which are formed could be washed out (in aqueous) or filtered from the reaction vessel and the remainder of the aqueous solvent (where applicable) azeotroped off with some of the telescoping solvent. In the formation of compound (XIV), if the alkoxide used to introduce OR3 is dissolved in solvent (such as ethanol), then this solvent could again be azeotroped off with some of the telescoping solvent. If solid alkoxide is used then this latter azeotroping step is not required. Most preferably the telescoping solvent for any telescoped steps of scheme 3 is toluene.
It will be appreciated that salts of the compounds of Schemes 1 to 3 can be formed in accordance with the invention by converting the relevant compound to a salt thereof (either in situ or as a separate step). Also an acid addition salt of the compound of formula (I) can be formed in accordance with the invention.
1.4. Clearly, for certain compounds of formulae (I), (IA) or (IB) wherein R13 is OR3, by exploiting the cyclisation and alkoxide exchange methodology described in sections 1.2 and 2.1 herein, it may be particularly advantageous to generate a compound of formula (I), (IA) or (IB) from a compound of the general formula (IXCa), wherein the 2-alkoxy group of the 5-(pyridin-3-yl) substituent in the former is different from that in the latter, directly in a xe2x80x9cone-pot reactionxe2x80x9d. To achieve this an alternative alcohol (R3OH) should be used wherein the alkyl chain of the xe2x80x94R3 group of the alcohol is different from that of the xe2x80x94R3a group on the starting compound of general formula (IXCa). When the alcohol which is to provide the alternative 2-alkoxy group (xe2x80x94OR3) is too scarce or expensive to be employed as the reaction solvent, then it will be expedient to use a suitable alternative such as 1,4-dioxan as reaction solvent with the required alcohol (R3aOH) present in an amount sufficient to effect the desired conversion, typically from about 1 to about 2 molecular equivalents. (IXCa) and R3a are as defined hereinbefore.
2. In a further generally applicable process, compounds of the general formula (I), (IA) or (IB) may be prepared from xe2x80x9calternativexe2x80x9d compounds of the general formula (I), (IA) or (IB) wherein said process may comprise either interconversion of differing xe2x80x94OR3 groups, interconversion of X and xe2x80x94OR3 groups or interconversion of xe2x80x94OR3 and xe2x80x94NR5R6 groups wherein X, R3 and NR5R6 are as defined hereinbefore.
2.1 As mentioned earlier, certain compounds of formulae (I), (IA) and (IB) can be interconverted by inducing alkoxide exchange or displacement at the 2-position of the 5-(pyridin-3-yl) substituent. This may be achieved, by treating the appropriate alcohol (of formula R3a OH wherein the R3a alkyl group is as defined hereinbefore and is different from the R3 group on the starting material (I), (IA) or (IB) with an alkali metal salt of a sterically hindered alcohol or amine in order to generate the required alkoxide anion which then reacts with the substrate. Typically, in a two-step procedure, a mixture of from about 1 to about 8, more preferably from about 5 to about 8, and especially from about 4 to about 8 molecular equivalents of potassium bis(trimethylsilyl)amide and the required alcohol (of formula R3a OH) as solvent is heated at from about 80xc2x0 C. to about 100xc2x0 C. for about 25 minutes to about 1 hour, followed by addition of the compound of formula (IA) or (IB) and heating of the reaction mixture at from about 100xc2x0 C. to about 130xc2x0 C. for from about 6 to about 24 hours. Alternatively, in a one-step procedure, the substrate may be treated directly, in the required alcohol as solvent, with from about 1.2 to about 6, preferably from about 4 to about 6 molecular equivalents of, for example, potassium bis(trimethylsilyl)amide, potassium t-butoxide or cesium carbonate at from about 80xc2x0 C. to about 130xc2x0 C. A hydroxide trapping agent may be optionally included in such alkoxide exchange reactions.
2.2 Alternatively, certain compounds of the general formula (I), (IA) or (IB) wherein R13 is xe2x80x94OR3 may be obtained from compounds of the general formula (XXX): 
wherein R1, R2, R4 are as defined previously herein and wherein X is anything other than xe2x80x94OR3 by reaction in the presence of xe2x80x94OR3xe2x88x92 optionally in the presence of a hydroxide trapping agent as defined hereinbefore.
2.3 In a yet further alternative synthesis compounds of the general formula (I), (IA) or (IB) wherein R13 is NR5R6 may be generated directly from a compound of general formula (I) wherein R13 =OR3. When R13 is OR3, the substrate may be treated with an excess of R5R6NH, or a suitable acid addition salt thereof, in the presence of an excess of a non-nucleophilic base such as a sterically hindered amine or a suitable inorganic base in a suitable solvent. Typically, R5R6NH is used as the free base with about a 3-fold excess (over the substrate) of potassium bis(trimethylsilyl)amide (KHMDS) in dimethylformamide (DMF) as solvent at about 100xc2x0 C. Alternatively, an excess of R5R6NH may be used as the solvent and the reaction conducted in the presence of about a 50% excess of copper(II) sulphate at up to the reflux temperature of the reaction medium. Where the desired amino substituent on the compound of the formula (I), (IA) or (IB) is xe2x80x94NR R6 and one of either R5 or R6 is H, then the exchange reaction may be carried out by refluxing with the appropriate amine, and copper (II) sulphate penta- or hepta-hydrate or anhydrous copper (II) sulphate or KHDMS in DMF. Typically, to exchange the OR3 group for alternative amines of the formula NHR5R6, such as compounds wherein R5 or R6 are selected from aliphatic or cyclic amines, optionally including oxygen (e.g. morpholine), then the reaction is preferably carried out by treating with the appropriate amine and about 3 equivalents of potassium bis(trimethylsilyl)amide in DMF for about 18 hours at 100xc2x0 C.
3. In a yet further alternative process, a compound of the general formula (I) may be prepared from a compound of general formulae (IIA) or (IIC) respectively: 
wherein Y is halo, preferably chloro, and R1, R2, R3, R5 and R6 are as previously defined for formulae (IXA) and (IXC), by a reaction with a 4-R1-piperazinyl compound as described for the preparation of compounds of formula (XA) and (XB) from compounds of formula (VIIA) and (VIIIB) respectively.
Alternatively, a compound of the general formula (I), (IA) or (IB) may be prepared from a compound of the general formula (IIB): 
wherein R1, R2, R4 and X are as previously defined herein via reaction with a 4-R10 piperazinyl compound followed by an optional displacement reaction in the presence of a hydroxide trapping agent and xe2x80x94OR3xe2x88x92 as detailed hereinbefore for the preparation of compound (I) from compound (IXB) or (XXX).
3.1 A compound of general formulae (IIA) or (IIB) or (IIC) may be prepared from a compound of general formula (IVA) or (IVB) or (IVC) respectively: 
wherein R1, R2, R3, R5, R6 and X are as previously herein, by the application of known methods for converting amino to a SO2Y group wherein Y is also as previously defined for formulae (IIA), (IIB) and (IIC). Such reactions are previously described for the preparation of compounds of the general formulae (VIIIA) and (VIIIB) from compounds of the general formulae (XIA) and (XIB) respectively.
A compound of the general formula (IVA) or (IVB) or (IVC) may be prepared by cyclisation of a compound of the general formula (VA) or (VB) or (VC) respectively: 
wherein R1, R2, R3, R5, R6 and X are as previously defined herein and wherein the conditions for cyclisation are analogous to those previously described for cyclisation of the compounds of general formulae (IXA), (IXB) or (IXC).
A compound of formula (VA) or (VB) or (VC) may be prepared by reduction of a compound of formula (VIA) or (VIB) or (IVC) respectively: 
wherein R1, R2, R3, R5, R6 and X are as previously defined for compounds of the general formulae (VA), (VB) and (VC), by conventional catalytic or catalytic transfer hydrogenation procedures as previously detailed for preparation of compounds of the general formulae (XIA) or (XIB) from compounds of the general formulae (XIIA) or (XIIB) respectively. A compound of formula (VIA), (VIB) or (VIC) may be prepared by reaction of a compound of formula (VII) as defined previously herein with a compound of formula (XIIA) or (XIIB) or (XIIC) respectively: 
wherein R3, R5, R6 and X are as previously defined for compounds of the general formulae (VIA) or (VIB) or (VIC). Again, as previously detailed a conventional amine protecting group strategy is preferred for (XIIA) when NR5R6 is a primary or secondary amino group. The coupling reaction is analogous to the reactions of (VII) with the compounds of general formulae (XA) or (XB) or (XC) already described herein.
3.2 A compound of general formulae (IIA) or (IIB) or (IIC) may be prepared from a compound of formula (IVA) or (IVB) or (IVC) respectively as described hereinbefore wherein said compound of the general formulae (IVA) or (IVB) or (IVC) may be prepared by direct cyclisation of a compound of the general formula (VIA) or (VIB) or (VIC) respectively: 
wherein R1, R2, R3, R5, R6 and X are as previously herein and wherein the conditions for said direct cyclisation are analogous to the previously described cyclisation for compounds of the general formulae (IXA) or (IXB) or (IXC) and wherein said cyclisation is followed by reduction of the resultant intermediate compounds according to the methods previously detailed herein to provide compounds of the general formulae (IVA) or (IVB) or (IVC) from compounds of the general formulae (VA) or (VB) or (VC).
Compounds of the general formula (XIIC) wherein X is Cl may be prepared from 2-hydroxy nicotinic acid via nitration followed by esterification then chlorination of the suitably protected nicotinic acid and subsequent ester hydrolysis.
Compounds of the general formula (XIIIC) (i.e. compounds of general formula (XIIIB wherein X is xe2x80x94OR3) can be prepared by analogy with the methods detailed previously herein.
4. A further, generally applicable, synthetic route to compounds of the general formula (I), (IA) or (IB) involves incorporation of the R1 substituent in the final step of the synthesis. Thus a compound of the general formula (I), (IA) or (IB) may be prepared by alkylation of a compound of formula (Ia), (IAa) or (IBa) wherein R1 is hydrogen and R2, R13 and R4 are as previously defined for formulae (I), (IA) and (IB), using one or more of a plethora of well-known methods, such as:
(i) reaction with a compound of formula R1J, wherein R1 is as previously defined for compounds of general formulae (I), (IA) and (IB), and J is a suitable leaving group, e.g. halo (preferably chloro, bromo or iodo), C1-C4 alkanesulphonyloxy, trifluoromethanesulphonyloxy or arylsulphonyloxy (such as benzenesulphonyloxy or p-toluenesulphonyloxy), in the presence of an appropriate base, optionally in the presence of sodium iodide or potassium iodide, at from about xe2x88x9270xc2x0 C. to about 100xc2x0 C. Preferably the alkylation is conducted at from about room temperature to about 120xc2x0 C. Suitable base-solvent combinations may be selected from:
(a) sodium, potassium or cesium carbonate, sodium or potassium bicarbonate, or a tertiary amine such as triethylamine or pyridine, together with a C1 to C4 alkanol, 1,2-dimethoxyethane, tetrahydrofuran, 1,4-dioxan, acetonitrile, pyridine, N,N-dimethylformamide or N,N-dimethylacetamide;
(b) sodium or potassium hydroxide, or a sodium or potassium C1 to C4 alkoxide, together with a C1 to C4 alkanol, water or mixtures thereof;
(c) lithium, sodium or potassium hydride, lithium, sodium or potassium bis(trimethylsilyl)amide, lithium diisopropylamide or butyllithium, together with toluene, ether, 1,2-dimethoxyethane, tetrahydrofuran or 1,4-dioxan; or
(d) under phase transfer catalysis conditions, a tetraalkylammonium halide or hydroxide, together with a mixture of an aqueous solution of sodium or potassium hydroxide and dichloromethane, 1,2-dichloroethane or chloroform;
xe2x80x83Typically, either about a 10% excess of sodium hydride is added to a solution of the substrate in a suitable solvent, e.g. anhydrous tetrahydrofuran or cesium carbonate in dimethylformamide (DMF) is employed, and the resulting anion treated with about a 10% excess of the required R1J.
(ii) reaction with a compound of formula R1OH, wherein R1 is as previously defined for compounds of the general formulae (I), (IA) and (IB), using classical Mitsunobu methodology. Typical reaction conditions involve treating the substrate with the alkanol in the presence of a triarylphosphine and a di(C1 to C4)alkyl azodicarboxylate, in a suitable solvent such as tetrahydrofuran or 1,4-dioxan, at from about xe2x88x925xc2x0 C. to about room temperature.
(iii) reaction with a compound of formula R1M, wherein R1 represents optionally substituted phenyl, Het2, Het3 or Het4 and wherein said Het groups are either aromatic or partially unsaturated at the C atom that is attached to M, and wherein M represents an optionally substituted metal or boron group wherein said metal or boron group is suitable for cross-coupling reactions (of metal or boron compounds), for example a dihydroxyborane, in the presence of an appropriate catalyst system (e.g. copper (II) acetate) or under so-called xe2x80x9cGoldbergxe2x80x9d conditions. Such cross-coupling is preferably carried out in the presence of a suitable base (e.g. pyridine), and a drying agent, typically 4 xc3x85 molecular sieves, in a suitable solvent such as dichloromethane or N-methylpyrrolidine, and optionally under microwave irradiation.
(iv) reaction with a compound of formula R1E, where E is halo, preferably bromo, under conditions suitable for cross-coupling of halogenated compounds, where R1 is as defined in (iii). Such reaction is typically carried out in the presence of an appropriate catalyst system (e.g. Palladium catalyst), in the presence of a suitable base, such as for example sodium t-butoxide, in a suitable solvent, such as toluene, with heating, typically at about 70xc2x0 C.
4.1 Thus, a compound of general formula (Ia), (IAa) or (IBa), wherein R1 is hydrogen and R2, R13 and R4 are as previously defined for compounds of general formulae (1), (IA) or (IB), may be obtained from a compound of formula (IXAa) or (IXBa) or (IXCa) respectively wherein R1 is hydrogen, and R2, R3, R5, R6 and R4 and X are as previously defined for formulae (IXA), (IXB) or (IXC), under the same conditions as those used for the conversion of a compound of the general formula (IXA), (IXB) or (IXC) to a compound of the general formula (I), (IA) or (IB) respectively when R1 is other than hydrogen, followed by acidification of the reaction mixture to a pH of about 6.
4.2 In a further alternative, generally applicable synthetic route the compounds of the present invention may be prepared by cyclisation of compounds of the general formulae (IXA), (IXB) or (IXC) wherein said compounds of the general formulae (IXA), (IXB) or (IXC) are obtained from compounds of the general formulae (IXAa), (IXBa) or (IXCa) wherein R1 is hydrogen and R2, R3, R5, R6 and R4 are as previously defined herein, using one or more of a plethora of well-known methods such as are detailed hereinbefore for conversion of compounds of the general formulae (Ia), (IAa) and (IBa) to compounds of the general formulae (I), (IA) and (IB). Any of the previously detailed methods for such general conversion may be used. Preferred conditions for such conversion use either from about 1.0 to 1.3 equivalents of sodium hydride in tetrahydrofuran solvent at from about xe2x88x9278xc2x0 to about room temperature and from about 1.1 to about 2.3 equivalents of alkylating agent at from about 60xc2x0 C. to about 70xc2x0 C., or from about 2.2 equivalents of cesium carbonate as base in dimethylformamide as solvent and about 1.1. equivalent of alkylating agent at about 60xc2x0 C.
5. In a yet further alternative synthesis, compounds of the general formula (I), (IA) or (IB) can be obtained from compounds of the general formula (I) wherein R10 is H, via a suitable alkylation reaction such as for example with an alkyl halide and a suitable base e.g. cesium carbonate and methyl chloride.
In a preferred process for the preparation of the compounds according to the present invention compounds of general formula (VIIB) are prepared from compounds of the general formula (XIIIB) according to the process detailed in Preparations 96(a) to (h). These compounds of general formula (VIIB) are coupled with compounds of general formula (XC) according to the process detailed in Preparations 29 and 96(i) to provide a compound of general formula (IXC), wherein said compound of general formula (IXC) is prepared according to the process detailed in Preparation 95. The compound of general formula (IXC) is then preferably cyclised under basic conditions according to the process detailed in Examples 8 and 102 to form compounds of general formula (IB) wherein R13 is OR3.
The 4-aminopyrazole-5-carboxamides of general formulae (VII), (VIIA) and (VIIB), the pyrazoles of general formula (XIII), the carboxylic acids of formulae (XA), (XB), (XIIA), (XIIB), (XIIC), (VIIA), (VIIB), (VIIC) and (X), or the compounds of the general formula R1J and R1E when neither commercially available nor subsequently described, can be obtained either by analogy with the processes described in the Preparations section or by conventional synthetic procedures, in accordance with standard textbooks on organic chemistry or literature precedent, from readily accessible starting materials using appropriate reagents and reaction conditions.
Moreover, persons skilled in the art will be aware of variations of, and alternatives to, those processes described hereinafter in the Examples and Preparations sections which allow the compounds defined by formulae (I), (IA) or (IB) to be obtained.
The pharmaceutically acceptable acid addition salts of the compounds of formulae (I), (IA) or (IB) which contain a basic centre may also be prepared in a conventional manner. By way of illustration, acid addition salts of compounds of formula (I) (more particularly IA and IB) can be formed by reacting a compound of formula (I) with an equimolar or excess amount of the appropriate acid, either neat or in a suitable solvent. The salt may then be precipitated out of solution and isolated by filtration or the reaction solvent can be stripped off by conventional means such as by evaporation under vacuum. Typical salts which can be used in the schemes of 1 to 3 are given in PCT/IB99/00519. Example of salts of compounds IA and IB are the p-toluenesulfonate, benzenesulfonate, camphorsulfonate and ethanesulfonate respectively.
Pharmaceutically acceptable base addition salts can be obtained in an analogous manner by treating a solution of a compound of formula (I), (IA) or (IB) with the appropriate base. Both types of salt may be formed or interconverted using ion-exchange resin techniques.
The present invention also includes all suitable isotopic variations of a compound of the formula (I) or a pharmaceutically acceptable salt thereof. An isotopic variation of a compound of the formula (I) or a pharmaceutically acceptable salt thereof is defined as one in which at least one atom is replaced by an atom having the same atomic number but an atomic mass different from the atomic mass usually found in nature. Examples of isotopes that can be incorporated into compounds of the formula (I) and pharmaceutically acceptable salts thereof include isotopes of hydrogen, carbon, nitrogen, oxygen, phosphorus, sulphur, fluorine and chlorine such as 2H, 3H, 13C, 14C, 15N, 17O, 18O, 31p, 32p, 35S, 18F and 36Cl, respectively. Certain isotopic variations of the compounds of the formula (I) and pharmaceutically acceptable salts thereof, for example, those in which a radioactive isotope such as 3H or 14C is incorporated, are useful in drug and/or substrate tissue distribution studies. Tritiated, i.e., 3H, and carbon-14, i.e., 14C, isotopes are particularly preferred for their ease of preparation and detectability. Further, substitution with isotopes such as deuterium, i.e., 2H, may afford certain therapeutic advantages resulting from greater metabolic stability, for example, increased in vivo half-life or reduced dosage requirements and hence may be preferred in some circumstances. Isotopic variations of the compounds of formula (I) and pharmaceutically acceptable salts thereof of this invention can generally be prepared by conventional procedures such as by the illustrative methods or by the preparations described in the Examples and Preparations hereafter using appropriate isotopic variations of suitable reagents.
It will be appreciated by those skilled in the art that certain protected derivatives of compounds of the formulae (I), (IA) or (IB), which may be made prior to a final de-protection stage, may not possess pharmacological activity as such, but may, in certain instances, be administered orally or parenterally and thereafter metabolised in the body to form compounds of the invention which are pharmacologically active. Such derivatives may therefore be described as xe2x80x9cpro-drugsxe2x80x9d. Further, certain compounds of the formulae (I), (IA) or (IB) may act as pro-drugs of other compounds of the formulae (I), (IA) or (IB).
All protected derivatives, and pro-drugs, of compounds of general formulae (I), (IA) or (IB) are included within the scope of the invention. Suitable protecting groups for use in accordance with the invention can be found in xe2x80x9cProtecting Groupsxe2x80x9d edited by P. J. Kocienski, Thieme, N.Y., 1994 xe2x80x94see particularly chapter 4, page 118-154 for carboxy protectng groups; and xe2x80x9cProtective Groups in Organic Synthesisxe2x80x9d 2nd edition, T. W. Greeene and P. G. M. Wutz, Wiley-Interscience (1991)xe2x80x94see particularly chapter 5 for carboxy protecting groups. Examples of suitable pro-drugs for the compounds of the present invention are described in Drugs of Today, Volume 19, Number 9, 1983, pp 499-538 and in Topics in Chemistry, Chapter 31, pp 306-316.
The biological activities of the compounds of the present invention were determined by the following test methods.
Phosihodiesterase (PDE) Inhibitory Activity
The compounds of the present invention are potent and selective cGMP PDE5 inhibitors. In vitro PDE inhibitory activities against cyclic guanosine 3xe2x80x2,5xe2x80x2-monophosphate (cGMP) and cyclic adenosine 3xe2x80x2,5xe2x80x2-monophosphate (cAMP) phosphodiesterases were determined by measurement of their IC50 values (the concentration of compound required for 50% inhibition of enzyme activity).
The required PDE enzymes were isolated from a variety of sources, including human corpus cavernosum, human and rabbit platelets, human cardiac ventricle, human skeletal muscle and bovine retina, essentially by the method of W. J. Thompson and M. M. Appleman (Biochem., 1971, 10, 311). In particular, the cGMP-specific PDE (PDE5) and the cGMP-inhibited cAMP PDE (PDE3) were obtained from human corpus cavernosum tissue, human platelets or rabbit platelets; the cGMP-stimulated PDE (PDE2) was obtained from human corpus cavernosum; the calcium/calmodulin (Ca/CAM)-dependent PDE (PDE1) from human cardiac ventricle; the cAMP-specific PDE (PDE4) from human skeletal muscle; and the photoreceptor PDE (PDE6) from bovine retina. Phosphodiesterases 7-11 were generated from full length human recombinant clones transfected into SF9 cells.
Assays were performed either using a modification of the xe2x80x9cbatchxe2x80x9d method of W. J. Thompson et al. (Biochem., 1979, 18, 5228) or using a scintillation proximity assay for the direct detection of AMP/GMP using a modification of the protocol described by Amersham plc under product code TRKQ7090/7100. In summary, the effect of PDE inhibitors was investigated by assaying a fixed amount of enzyme in the presence of varying inhibitor concentrations and low substrate, (cGMP or cAMP in a 3:1 ratio unlabelled to [3H]-labeled at a conc xcx9c1/3 Km) such that IC50≅Ki. The final assay volume was made up to 100 xcexcl with assay buffer [20 mM Tris-HCl pH 7.4, 5 mM MgCl2, 1 mg/ml bovine serum albumin]. Reactions were initiated with enzyme, incubated for 30-60 min at 30xc2x0 C. to give  less than 30% substrate turnover and terminated with 50 xcexcl yttrium silicate SPA beads (containing 3 mM of the respective unlabelled cyclic nucleotide for PDEs 9 and 11). Plates were re-sealed and shaken for 20 min, after which the beads were allowed to settle for 30 min in the dark and then counted on a TopCount plate reader (Packard, Meriden, Conn.) Radioactivity units were converted to % activity of an uninhibited control (100%), plotted against inhibitor concentration and inhibitor IC50 values obtained using the xe2x80x98Fit Curvexe2x80x99 Microsoft Excel extension. Results from these tests show that the compounds of the present invention are potent and selective inhibitors of cGMP-specific PDE5.
Preferred compounds of the present invention, such as those of Examples 3-12, 14-17, 19, 21-30, 32, 33, 35-46, 48-59, 61, 62, 65-75, 77, 79-102 have IC50 values of less than about 10 nM for the PDE5 enzyme. More preferred compounds, such as those of Examples 3-12, 14, 15, 17, 23-30, 32, 33, 35-46, 48, 50-59, 61, 62, 65, 69-74, 79-102 have IC50 values of less than about 5 nM for the PDE5 enzyme. Especially preferred compounds, such as those of Examples 4-10, 15, 17, 23-28, 30, 32, 33, 35-42, 44, 45, 46, 50, 52-56, 58, 59, 61, 62, 65, 69-74, 79-93, 96, 98-102 have IC50 values of less than about 2 nM for the PDE5 enzyme.
Especially preferred herein are compounds which have an IC50 value of less than about 10, more preferably less than about 5, and most preferably less than about 2 nM for the PDE5 enzyme in combination with selectivity of greater than 10-fold, more preferably greater than 50-fold, more preferably greater than 100-fold and especially greater than 200-fold selectivity for the PDE5 enzyme versus the PDE6 enzyme.
Functional Activity
This was assessed in vitro by determining the capacity of a compound of the invention to enhance sodium nitroprusside-induced relaxation of pre-contracted rabbit corpus cavernosum tissue strips, as described by S. A. Ballard et al. (Brit. J. Pharmacol., 1996, 118 (suppl.), abstract 153P).
In Vivo Activity
Compounds were screened in anesthetized dogs to determine their capacity, after i.v. administration, to enhance the pressure rises in the corpora cavernosa of the penis induced by intracavernosal injection of sodium nitroprusside, using a method based on that described by Trigo-Rocha et al. (Neurourol. and Urodyn., 1994, 13, 71).
The compounds of formulae (I), (IA) or (IB), their pharmaceutically acceptable salts, and pharmaceutically acceptable solvates of either entity can be administered alone but, in human therapy will generally be administered in admixture with a suitable pharmaceutical excipient diluent or carrier selected with regard to the intended route of administration and standard pharmaceutical practice. For example, the compounds of formulae (I), (IA) or (IB) or salts or solvates thereof can be administered orally, buccally or sublingually in the form of tablets, capsules (including soft gel capsules), ovules, elixirs, solutions or suspensions, which may contain flavouring or colouring agents, for immediate-, delayed-, modified-, or controlled-release such as sustained-, dual-, or pulsatile delivery applications. The compounds of the invention may also be administered via intracavernosal injection. The compounds of the invention may also be administered via fast dispersing or fast dissolving dosages forms or in the form of a high energy dispersion or as coated particles. Suitable pharmaceutical formulations of the compounds of the invention may be in coated or un-coated form as desired.
Such tablets may contain excipients such as microcrystalline cellulose, lactose, sodium citrate, calcium carbonate, dibasic calcium phosphate, glycine and starch (preferably corn, potato or tapioca starch), disintegrents such as sodium starch glycollate, croscarmellose sodium and certain complex silicates, and granulation binders such as polyvinylpyrrolidone, hydroxypropylmethyl cellulose (HPMC), hydroxypropylcellulose (HPC), sucrose, gelatin and acacia. Additionally, lubricating agents such as magnesium stearate, stearic acid, glyceryl behenate and talc may be included.
Solid compositions of a similar type may also be employed as fillers in gelatin capsules. Preferred excipients in this regard include lactose, starch, a cellulose, milk sugar or high molecular weight polyethylene glycols. For aqueous suspensions and/or elixirs, the compounds of the formula (I), (IA) or (IB) may be combined with various sweetening or flavouring agents, colouring matter or dyes, with emulsifying and/or suspending agents and with diluents such as water, ethanol, propylene glycol and glycerin, and combinations thereof.
Modified release and pulsatile release dosage forms may contain excipients such as those detailed for immediate release dosage forms together with additional excipients that act as release rate modifiers, these being coated on and/or included in the body of the device. Release rate modifiers include, but are not exclusively limited to, hydroxypropylmethyl cellulose, methyl cellulose, sodium carboxymethylcellulose, ethyl cellulose, cellulose acetate, polyethylene oxide, Xanthan gum, Carbomer, ammonio methacrylate copolymer, hydrogenated castor oil, carnauba wax, paraffin wax, cellulose acetate phthalate, hydroxypropylmethyl cellulose phthalate, methacrylic acid copolymer and mixtures thereof. Modified release and pulsatile release dosage forms may contain one or a combination of release rate modifying excipients. Release rate modifying excipients maybe present both within the dosage form i.e. within the matrix, and/or on the dosage form i.e. upon the surface or coating.
Fast dispersing or dissolving dosage formulations (FDDFs) may contain the following ingredients: aspartame, acesulfame potassium, citric acid, croscarmellose sodium, crospovidone, diascorbic acid, ethyl acrylate, ethyl cellulose, gelatin, hydroxypropylmethyl cellulose, magnesium stearate, mannitol, methyl methacrylate, mint flavouring, polyethylene glycol, fumed silica, silicon dioxide, sodium starch glycolate, sodium stearyl fumarate, sorbitol, xylitol. The terms dispersing or dissolving as used herein to describe FDDFs are dependent upon the solubility of the drug substance used i.e. where the drug substance is insoluble a fast dispersing dosage form can be prepared and where the drug substance is soluble a fast dissolving dosage form can be prepared.
The compounds of the invention can also be administered parenterally, for example, intracavernosally, intravenously, intra-arterially, intraperitoneally, intrathecally, intraventricularly, intraurethrally intrasternally, intracranially, intramuscularly or subcutaneously, or they may be administered by infusion or needless injection techniques. For such parenteral administration they are best used in the form of a sterile aqueous solution which may contain other substances, for example, enough salts or glucose to make the solution isotonic with blood. The aqueous solutions should be suitably buffered (preferably to a pH of from 3 to 9), if necessary. The preparation of suitable parenteral formulations under sterile conditions is readily accomplished by standard pharmaceutical techniques well-known to those skilled in the art.
For oral and parenteral administration to human patients, the daily dosage level of the compounds of formula (I), (IA) or (IB) or salts or solvates thereof will usually be from 10 to 500 mg (in single or divided doses).
Thus, for example, tablets or capsules of the compounds of formulae (I), (IA) or (IB) or salts or solvates thereof may contain from 5mg to 250 mg of active compound for administration singly or two or more at a time, as appropriate. The physician in any event will determine the actual dosage which will be most suitable for any individual patient and it will vary with the age, weight and response of the particular patient. The above dosages are exemplary of the average case. There can, of course, be individual instances where higher or lower dosage ranges are merited and such are within the scope of this invention. The skilled person will also appreciate that, in the treatment of certain conditions (including MED and FSD), compounds of the invention may be taken as a single dose on an xe2x80x9cas requiredxe2x80x9d basis (i.e. as needed or desired).
Such tablets can be manufactured by standard processes, for example, direct compression or a wet or dry granulation process. The tablet cores may be coated with appropriate overcoats.
The compounds of the invention can also be administered intranasally or by inhalation and are conveniently delivered in the form of a dry powder inhaler or an aerosol spray presentation from a pressurized container, pump, spray or nebulizer with the use of a suitable propellant, e.g. dichlorodifluoromethane, trichlorofluoromethane, dichlorotetrafluoroethane, a hydrofluoroalkane such as 1,1,1,2-tetrafluoroethane (HFA 134A [trade mark] or 1,1,1,2,3,3,3-heptafluoropropane (HFA 227EA [trade mark]), carbon dioxide or other suitable gas. In the case of a pressurized aerosol, the dosage unit may be determined by providing a valve to deliver a metered amount. The pressurized container, pump, spray or nebulizer may contain a solution or suspension of the active compound, e.g. using a mixture of ethanol and the propellant as the solvent, which may additionally contain a lubricant, e.g. sorbitan trioleate. Capsules and cartridges (made, for example, from gelatin) for use in an inhaler or insufflator may be formulated to contain a powder mix of a compound of the formula (I), (IA) or (IB) and a suitable powder base such as lactose or starch.
Aerosol or dry powder formulations are preferably arranged so that each metered dose or xe2x80x9cpuffxe2x80x9d contains from 1 to 50 mg of a compound of the formula (I), (IA) or (IB) for delivery to the patient. The overall daily dose with an aerosol will be in the range of from 1 to 50 mg which may be administered in a single dose or, more usually, in divided doses throughout the day.
The compounds of the invention may also be formulated for delivery via an atomizer. Formulations for atomizer devices may contain the following ingredients as solubilities, emulsifiers or suspending agents: water, ethanol, glycerol, propylene glycol, low molecular weight polyethylene glycols, sodium chloride, fluorocarbons, polyethylene glycol ethers, sorbitan trioleate, oleic acid.
Alternatively, the compounds of the formulae (I), (IA) or (IB) or salts or solvates thereof can be administered in the form of a suppository or pessary, or they may be applied topically in the form of a gel, hydrogel, lotion, solution, cream, ointment or dusting powder. The compounds of the formulae (IA) and (IB) or salts or solvates thereof may also be dermally administered. The compounds of the formulae (I), (IA) or (IB) or salts or solvates thereof may also be transdermally administered, for example, by the use of a skin patch. They may also be administered by the ocular, pulmonary or rectal routes.
For ophthalmic use, the compounds can be formulated as micronized suspensions in isotonic, pH adjusted, sterile saline, or, preferably, as solutions in isotonic, pH adjusted, sterile saline, optionally in combination with a preservative such as a benzylalkonium chloride. Alternatively, they may be formulated in an ointment such as petrolatum.
For application topically to the skin, the compounds of the formulae (I), (IA) or (IB) or salts or solvates thereof can be formulated as a suitable ointment containing the active compound suspended or dissolved in, for example, a mixture with one or more of the following: mineral oil, liquid petrolatum, white petrolatum, propylene glycol, polyoxyethylene polyoxypropylene compound, emulsifying wax and water. Alternatively, they can be formulated as a suitable lotion or cream, suspended or dissolved in, for example, a mixture of one or more of the following: mineral oil, sorbitan monostearate, a polyethylene glycol, liquid paraffin, polysorbate 60, cetyl esters wax, cetearyl alcohol, 2-octyldodecanol, benzyl alcohol and water.
The compounds of the formulae (I), (IA) or (IB) may also be used in combination with a cyclodextrin. Cyclodextrins are known to form inclusion and non-inclusion complexes with drug molecules. Formation of a drug-cyclodextrin complex may modify the solubility, dissolution rate, bioavailability and/or stability property of a drug molecule. Drug-cyclodextrin complexes are generally useful for most dosage forms and administration routes. As an alternative to direct complexation with the drug the cyclodextrin may be used as an auxiliary additive, e.g. as a carrier, diluent or solubilizes. Alpha-, beta- and gamma-cyclodextrins are most commonly used and suitable examples are described in WO-A-91/11172, WO-A-94/02518 and WO-A-98/55148.
Generally, in humans, oral administration of the compounds of the invention is the preferred route, being the most convenient and, for example in MED, avoiding the well-known disadvantages associated with intracavernosal (i.c.) administration. A preferred oral dosing regimen in MED for a typical man is from 5 to 250 mg of compound when required. In circumstances where the recipient suffers from a swallowing disorder or from impairment of drug absorption after oral administration, the drug may be administered parenterally, sublingually or buccally.
For veterinary use, a compound of formula (I), (IA) or (IB), or a veterinarily acceptable salt thereof, or a veterinarily acceptable solvate or pro-drug thereof, is administered as a suitably acceptable formulation in accordance with normal veterinary practice and the veterinary surgeon will determine the dosing regimen and route of administration which will be most appropriate for a particular animal.
It is to be appreciated that all references herein to treatment include curative, palliative and prophylactic treatment.
Thus the invention provides a pharmaceutical composition comprising a compound of formula (I), (IA) or (IB), or a pharmaceutically acceptable salt thereof, or a pharmaceutically acceptable solvate or pro-drug thereof, together with a pharmaceutically acceptable diluent or carrier.
It further provides a veterinary formulation comprising a compound of formula (I), (IA) or (IB), or a veterinarily acceptable salt thereof, or a veterinarily acceptable solvate or pro-drug thereof, together with a veterinarily acceptable diluent or carrier.
The invention also provides a compound of formula (I), (IA) or (IB), or a pharmaceutically acceptable salt thereof, or a pharmaceutically acceptable solvate or pro-drug thereof, or a pharmaceutical composition containing any of the foregoing, for use as a human medicament.
In addition, it provides a compound of formula (I), (IA) or (IB), or a veterinarily acceptable salt thereof, or a veterinarily acceptable solvate or pro-drug thereof, or a veterinary formulation containing any of the foregoing, for use as an animal medicament.
In yet another aspect, the invention provides the use of a compound of formula (I), (IA) or (IB), or a pharmaceutically acceptable salt thereof, or a pharmaceutically acceptable solvate or pro-drug thereof, for the manufacture of a human medicament for the curative, palliative or prophylactic treatment of a medical condition for which a cGMP PDE5 inhibitor is indicated. There is further provided the use of a compound of formula (I), (IA) or (IB) or a suitable salt, solvate or pro-drug thereof, in the manufacture of a medicament for the treatment of a medical condition in which inhibition of a cGMP PDE5 is desirable.
It also provides the use of a compound of formula (I), (IA) or (IB), or a veterinarily acceptable salt thereof, or a veterinarily acceptable solvate or pro-drug thereof, for the manufacture of an animal medicament for the curative, palliative or prophylactic treatment of a medical condition for which a cGMP PDE5 inhibitor is indicated.
Moreover, the invention provides the use of a compound of formula (I), (IA) or (IB), or a pharmaceutically acceptable salt thereof, or a pharmaceutically acceptable solvate or pro-drug thereof, for the manufacture of a human medicament for the curative, palliative or prophylactic treatment of male erectile dysfunction (MED), impotence, female sexual dysfunction (FSD), clitoral dysfunction, female hypoactive sexual desire disorder, female sexual arousal disorder, female sexual pain disorder, female sexual orgasmic dysfunction (FSOD), sexual dysfunction due to spinal cord injury, selective serotonin re-uptake inhibitor (SSRI) induced sexual dysfunction, premature labour, dysmenorrhoea, benign prostatic hyperplasia (BPH), bladder outlet obstruction, incontinence, stable, unstable and variant (Prinzmetal) angina, hypertension, pulmonary hypertension, chronic obstructive pulmonary disease, coronary artery disease, congestive heart failure, atherosclerosis, conditions of reduced blood vessel patency, peripheral vascular disease, stroke, nitrate induced tolerance, bronchitis, allergic asthma, chronic asthma, allergic rhinitis, diseases and conditions of the eye, diseases characterized by disorders of gut motility, pre-eclampsia, Kawasaki""s syndrome, nitrate tolerance, multiple sclerosis, diabetic nephropathy, neuropathy including autonomic and peripheral neuropathy and in particular diabetic neuropathy and symptoms thereof e.g. gastroparesis, Alzheimer""s disease, acute respiratory failure, psoriasis, skin necrosis, cancer, metastasis, baldness, nutcracker oesophagus, anal fissure, haemorrhoids, hypoxic vasoconstriction or blood pressure stabilization during haemodialysis. Particularly preferred conditions include MED and FSD.
It also provides the use of a compound of formula (I), (IA) or (IB), or a veterinarily acceptable salt thereof, or a veterinarily acceptable solvate or pro-drug thereof, for the manufacture of an animal medicament for the curative, palliative or prophylactic treatment of male erectile dysfunction (MED), impotence, female sexual dysfunction (FSD), clitoral dysfunction, female hypoactive sexual desire disorder, female sexual arousal disorder, female sexual pain disorder, female sexual orgasmic dysfunction (FSOD), sexual dysfunction due to spinal cord injury, selective serotonin re-uptake inhibitor (SSRI) induced sexual dysfunction, premature labour, dysmenorrhoea, benign prostatic hyperplasia (BPH), bladder outlet obstruction, incontinence, stable, unstable and variant (Prinzmetal) angina, hypertension, pulmonary hypertension, chronic obstructive pulmonary disease, coronary artery disease, congestive heart failure, atherosclerosis, conditions of reduced blood vessel patency, peripheral vascular disease, stroke, nitrate induced tolerance, bronchitis, allergic asthma, chronic asthma, allergic rhinitis, diseases and conditions of the eye, diseases characterized by disorders of gut motility, pre-eclampsia, Kawasaki""s syndrome, nitrate tolerance, multiple sclerosis, diabetic nephropathy, neuropathy including autonomic and peripheral neuropathy and in particular diabetic neuropathy and symptoms thereof, Alzheimer""s disease, acute respiratory failure, psoriasis, skin necrosis, cancer, metastasis, baldness, nutcracker oesophagus, anal fissure, haemorrhoids, hypoxic vasoconstriction or blood pressure stabilization during haemodialysis. Particularly preferred conditions include MED and FSD.
Additionally, the invention provides a method of treating or preventing a medical condition for which a cGMP PDE5 inhibitor is indicated, in a mammal (including a human being), which comprises administering to said mammal a therapeutically effective amount of a compound of formula (I), (IA) or (IB), or a tolerance, multiple sclerosis, diabetic nephropathy, neuropathy including autonomic and peripheral neuropathy and in particular diabetic neuropathy and symptoms thereof e.g. gastroparesis, Alzheimer""s disease, acute respiratory failure, psoriasis, skin necrosis, cancer, metastasis, baldness, nutcracker oesophagus, anal fissure, haemorrhoids, hypoxic vasoconstriction or blood pressure stabilization during haemodialysis. Particularly preferred conditions include MED and FSD.
It also provides the use of a compound of formula (I), (IA) or (IB), or a veterinarily acceptable salt thereof, or a veterinarily acceptable solvate or pro-drug thereof, for the manufacture of an animal medicament for the curative, palliative or prophylactic treatment of male erectile dysfunction (MED), impotence, female sexual dysfunction (FSD), clitoral dysfunction, female hypoactive sexual desire disorder, female sexual arousal disorder, female sexual pain disorder, female sexual orgasmic dysfunction (FSOD), sexual dysfunction due to spinal cord injury, selective serotonin re-uptake inhibitor (SSRI) induced sexual dysfunction, premature labour, dysmenorrhoea, benign prostatic hyperplasia (BPH), bladder outlet obstruction, incontinence, stable, unstable and variant (Prinzmetal) angina, hypertension, pulmonary hypertension, chronic obstructive pulmonary disease, coronary artery disease, congestive heart failure, atherosclerosis, conditions of reduced blood vessel patency, peripheral vascular disease, stroke, nitrate induced tolerance, bronchitis, allergic asthma, chronic asthma, allergic rhinitis, diseases and conditions of the eye, diseases characterized by disorders of gut motility, pre-eclampsia, Kawasaki""s syndrome, nitrate tolerance, multiple sclerosis, diabetic nephropathy, neuropathy including autonomic and peripheral neuropathy and in particular diabetic neuropathy and symptoms thereof, Alzheimer""s disease, acute respiratory failure, psoriasis, skin necrosis, cancer, metastasis, baldness, nutcracker oesophagus, anal fissure, haemorrhoids, hypoxic vasoconstriction or blood pressure stabilization during haemodialysis. Particularly preferred conditions include MED and FSD.
Additionally, the invention provides a method of treating or preventing a medical condition for which a cGMP PDE5 inhibitor is indicated, in a mammal (including a human being), which comprises administering to said mammal a therapeutically effective amount of a compound of formula (I), (IA) or (IB), or a female sexual dysfunction (FSD), clitoral dysfunction, female hypoactive sexual desire disorder, female sexual arousal disorder, female sexual pain disorder, female sexual orgasmic dysfunction (FSOD), sexual dysfunction due to spinal cord injury, selective serotonin re-uptake inhibitor (SSRI) induced sexual dysfunction, premature labour, dysmenorrhoea, benign prostatic hyperplasia (BPH), bladder outlet obstruction, incontinence, stable, unstable and variant (Prinzmetal) angina, hypertension, pulmonary hypertension, chronic obstructive pulmonary disease, coronary artery disease, congestive heart failure, atherosclerosis, conditions of reduced blood vessel patency, peripheral vascular disease, stroke, nitrate induced tolerance, bronchitis, allergic asthma, chronic asthma, allergic rhinitis, diseases and conditions of the eye, diseases characterized by disorders of gut motility, pre-eclampsia, Kawasaki""s syndrome, nitrate tolerance, multiple sclerosis, diabetic nephropathy, neuropathy including autonomic and peripheral neuropathy and in particular diabetic neuropathy and symptoms thereof e.g. gastroparesis, peripheral diabetic neuropathy, Alzheimer""s disease, acute respiratory failure, psoriasis, skin necrosis, cancer, metastasis, baldness, nutcracker oesophagus, anal fissure, haemorrhoids, hypoxic vasoconstriction or blood pressure stabilization of during haemodialysis in a mammal (including a human being).
The invention also includes any novel intermediates described herein, for example those of formulae (IXA), (IXB), (VIIA), (VIIB), (VII), (VIIIA) and (X).
The present invention additionally comprises the combined administration of a CGMP PDE5 inhibitor of the general formula (I), wherein said combined administration can be in the form of simultaneous, sequential or joint administration with:
(a) one or more naturally occurring or synthetic prostaglandins or esters thereof. Suitable prostaglandins for use herein include compounds such as alprostadil, prostaglandin E1, prostaglandin E0, 13,14-dihydroprosta glandin E1, prostaglandin E2, eprostinol, natural synthetic and semi-synthetic prostaglandins and derivatives thereof including those described in U.S. Pat. No. 6,037,346 issued on Mar. 14th 2000 and incorporated herein by reference, PGE0, PGE1, PGA1, PGB1, PGF1 xcex1, 19-hydroxy PGA, 19-hydroxy - PGB1, PGE2, PGB2, 19-hydroxy-PGA2, 19-hydroxy-PGB2, PGE3xcex1, carboprost tromethamine dinoprost, tromethamine, dinoprostone, lipo prost, gemeprost, metenoprost, sulprostune, tiaprost and moxisylate; and/or
(b) one or more xcex1-adrenergic receptor antagonist compounds also known as xcex1-adrenoceptors or xcex1-receptors or c:-blockers. Suitable compounds for use herein include: the xcex1-adrenergic receptors as described in PCT application WO99/30697 published on Jun. 14th 1998, the disclosures of which relating to xcex1-adrenergic receptors are incorporated herein by reference and include, selective xcex11-adrenoceptors or xcex12-adrenoceptors and non-selective adrenoceptors, suitable xcex11-adrenoceptors include: phentolamine, phentolamine mesylate, trazodone, alfuzosin, indoramin, naftopidil, tamsulosin, dapiprazole, phenoxybenzamine, idazoxan, efaraxan, yohimbine, rauwolfa alkaloids, Recordati 15/2739, SNAP 1069, SNAP 5089, RS17053, SL 89.0591, doxazosin, terazosin, abanoquil and prazosin; xcex12-blockers from U.S. Pat. No. 6,037,346 [Mar. 14th 2000] dibenarnine, tolazoline, trimazosin and dibenarnine; xcex1-adrenergic receptors as described in U.S. Pat. Nos. 4,188,390; 4,026,894; 3,511,836; 4,315,007; 3,527,761; 3,997,666; 2,503,059; 4,703,063; 3,381,009; 4,252,721 and 2,599,000 each of which is incorporated herein by reference; xcex12-Adrenoceptors include: clonidine, papaverine, papaverine hydrochloride, optionally in the presence of a cariotonic agent such as pirxamine; and/or
(c) one or more NO-donor (NO-agonist) compounds. Suitable NO-donor compounds for use herein include organic nitrates, such as mono- di or trinitrates or organic nitrate esters including glyceryl brinitrate (also known as nitroglycerin), isosorbide 5-mononitrate, isosorbide dinitrate, pentaerythritol tetranitrate, erythrityl tetranitrate, sodium nitroprusside (SNP), 3-morpholinosydnonimine molsidomine, S-nitroso- N-acetyl penicilliamine (SNAP) S-nitroso-N-glutathione (SNO-GLU), N-hydroxyxe2x80x94L-arginine, amylnitrate, linsidomine, linsidomine chlorohydrate, (SIN-1) S-nitrosoxe2x80x94N-cysteine, diazenium diolates,(NONOates), 1,5-pentanedinitrate, L-arginene, ginseng, zizphi fructus, molsidomine, Rexe2x80x942047, nitrosylated maxisylyte derivatives such as NMI-678-11 and NMI-937 as described in published PCT application WO 0012075 ; and/or
(d) one or more potassium channel openers. Suitable potassium channel openers for use herein include nicorandil, cromokalim, levcromakalim, lemakalim, pinacidil, cliazoxide, minoxidil, charybdotoxin, glyburide, 4-amini pyridine, BaCl2; and/or
(e) one or more dopaminergic agents. Suitable dopaminergic compounds for use herein include D2-agonists such as, pramipexol; apomorphine; and/or
(f) one or more vasodilator agents. Suitable vasodilator agents for use herein include nimodepine, pinacidil, cyclandelate, isoxsuprine, chloroprumazine, halo peridol, Rec 15/2739, trazodone, pentoxifylline; and/or
(g) one or more thromboxane A2 agonists; and/or
(h) one or more CNS active agents; and/or
(i) one or more ergot alkoloids; Suitable ergot alkaloids are described in U.S. Pat. No. 6,037,346 issued on Mar. 14th 2000 and include acetergamine, brazergoline, bromerguride, cianergoline, delorgotrile, disulergine, ergonovine maleate, ergotamine tartrate, etisulergine, lergotrile, lysergide, mesulergine, metergoline, metergotamine, nicergoline, pergolide, propisergide, proterguride, terguride; and/or
(k) one or more compounds which modulate the action of atrial natruretic factor (also known as atrial naturetic peptide), such as inhibitors or neutral endopeptidase; and/or
(l) one or more compounds which inhibit angiotensin-converting enzyme such as enapril, and combined inhibitors of angiotensin-converting enzyme and neutral endopeptidase such as omapatrilat; and/or
(m)one or more angiotensin receptor antagonists such as losartan; and/or
(n) one or more substrates for NO-synthase, such as L-arginine; and/or
(o) one or more calcium channel blockers such as amlodipine; and/or
(p) one or more antagonists of endothelin receptors and inhibitors or endothelin-converting enzyme; and/or
(q) one or more cholesterol lowering agents such as statins and fibrates; and/or
(r) one or more antiplatelet and antithrombotic agents, e.g. tPA, uPA, warfarin, hirudin and other thrombin inhibitors, heparin, thromboplastin activating factor inhibitors; and/or
(s) one or more insulin sensitising agents such as rezulin and hypoglycaemic agents such as glipizide; and/or
(t) L-DOPA or carbidopa; and/or
(u) one or more acetylcholinesterase inhibitors such as donezipil; and/or
(v) one or more steroidal or non-steroidal anti-inflammatory agents.